# lt.indices fails for wrong input

    x is not an object of class mortaar_life_table or mortaar_life_table_list.

# lt.indices produces the right output

    {
      "type": "list",
      "attributes": {
        "names": {
          "type": "character",
          "attributes": {},
          "value": ["child_i", "d5_9", "d10_14", "juvenile_i", "d5_14", "d20plus", "senility_i", "d0plus", "d60plus", "p5_19", "D30_D5", "D0_14_D", "d0_14", "e0"]
        }
      },
      "value": [
        {
          "type": "double",
          "attributes": {},
          "value": [1.83333]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [22]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [12]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [0.21935]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [34]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [155]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [0.27742]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [247]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [43]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [0.2132]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [0.5668]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [0.34008]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [84]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [30.67139]
        }
      ]
    }

---

    {
      "type": "list",
      "attributes": {
        "names": {
          "type": "character",
          "attributes": {},
          "value": ["corpus mandibulae", "margo orbitalis"]
        }
      },
      "value": [
        {
          "type": "list",
          "attributes": {
            "names": {
              "type": "character",
              "attributes": {},
              "value": ["child_i", "d5_9", "d10_14", "juvenile_i", "d5_14", "d20plus", "senility_i", "d0plus", "d60plus", "p5_19", "D30_D5", "D0_14_D", "d0_14", "e0"]
            }
          },
          "value": [
            {
              "type": "double",
              "attributes": {},
              "value": []
            },
            {
              "type": "double",
              "attributes": {},
              "value": []
            },
            {
              "type": "double",
              "attributes": {},
              "value": []
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.13966]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [7.5]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [53.7]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.26629]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [67.2]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [14.3]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.15032]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.69345]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.17113]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [11.5]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [37.88839]
            }
          ]
        },
        {
          "type": "list",
          "attributes": {
            "names": {
              "type": "character",
              "attributes": {},
              "value": ["child_i", "d5_9", "d10_14", "juvenile_i", "d5_14", "d20plus", "senility_i", "d0plus", "d60plus", "p5_19", "D30_D5", "D0_14_D", "d0_14", "e0"]
            }
          },
          "value": [
            {
              "type": "double",
              "attributes": {},
              "value": []
            },
            {
              "type": "double",
              "attributes": {},
              "value": []
            },
            {
              "type": "double",
              "attributes": {},
              "value": []
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.06421]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [4]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [62.3]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.15249]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [74.8]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [9.5]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.10101]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.69118]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.12701]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [9.5]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [34.7393]
            }
          ]
        }
      ]
    }

# helper function lt.mortality produces the right output

    {
      "type": "list",
      "attributes": {
        "names": {
          "type": "character",
          "attributes": {},
          "value": ["q0_5", "q10_5", "q15_5", "q15_45"]
        }
      },
      "value": [
        {
          "type": "double",
          "attributes": {},
          "value": [20.24291]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [6.85714]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [4.90798]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [68.57143]
        }
      ]
    }