# lt.representativity fails for wrong input

    x is not an object of class mortaar_life_table or mortaar_life_table_list.

# lt.representativity produces the right output

    {
      "type": "list",
      "attributes": {
        "names": {
          "type": "character",
          "attributes": {},
          "value": ["approach", "condition", "value1", "value2", "result", "outcome"]
        },
        "class": {
          "type": "character",
          "attributes": {},
          "value": ["data.frame"]
        },
        "row.names": {
          "type": "integer",
          "attributes": {},
          "value": [1, 2, 3, 4]
        }
      },
      "value": [
        {
          "type": "character",
          "attributes": {},
          "value": ["weiss_i1", "weiss_i2", "child_i", "juvenile_i"]
        },
        {
          "type": "character",
          "attributes": {},
          "value": ["5q0 > 5q15", "5q10 < 5q15", "(5D5 / 5D10) >= 2", "(10D5 / D20+) >= 0.1"]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [20.24, 4.91, 22, 34]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [6.86, 4.91, 12, 155]
        },
        {
          "type": "double",
          "attributes": {},
          "value": [4.12, 1.4, 1.83, 0.22]
        },
        {
          "type": "logical",
          "attributes": {},
          "value": [true, false, false, true]
        }
      ]
    }

---

    {
      "type": "list",
      "attributes": {
        "names": {
          "type": "character",
          "attributes": {},
          "value": ["corpus mandibulae", "margo orbitalis"]
        }
      },
      "value": [
        {
          "type": "list",
          "attributes": {
            "names": {
              "type": "character",
              "attributes": {},
              "value": ["approach", "condition", "value1", "value2", "result", "outcome"]
            },
            "class": {
              "type": "character",
              "attributes": {},
              "value": ["data.frame"]
            },
            "row.names": {
              "type": "integer",
              "attributes": {},
              "value": [1, 2, 3, 4]
            }
          },
          "value": [
            {
              "type": "character",
              "attributes": {},
              "value": ["weiss_i1", "weiss_i2", "child_i", "juvenile_i"]
            },
            {
              "type": "character",
              "attributes": {},
              "value": ["5q0 > 5q15", "5q10 < 5q15", "(5D5 / 5D10) >= 2", "(10D5 / D20+) >= 0.1"]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0, 7.5, 0, 7.5]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [53.7, 53.7, 53.7, 53.7]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.14, 0.14, 0.14, 0.14]
            },
            {
              "type": "logical",
              "attributes": {},
              "value": [true, true, true, true]
            }
          ]
        },
        {
          "type": "list",
          "attributes": {
            "names": {
              "type": "character",
              "attributes": {},
              "value": ["approach", "condition", "value1", "value2", "result", "outcome"]
            },
            "class": {
              "type": "character",
              "attributes": {},
              "value": ["data.frame"]
            },
            "row.names": {
              "type": "integer",
              "attributes": {},
              "value": [1, 2, 3, 4]
            }
          },
          "value": [
            {
              "type": "character",
              "attributes": {},
              "value": ["weiss_i1", "weiss_i2", "child_i", "juvenile_i"]
            },
            {
              "type": "character",
              "attributes": {},
              "value": ["5q0 > 5q15", "5q10 < 5q15", "(5D5 / 5D10) >= 2", "(10D5 / D20+) >= 0.1"]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0, 4, 0, 4]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [62.3, 62.3, 62.3, 62.3]
            },
            {
              "type": "double",
              "attributes": {},
              "value": [0.06, 0.06, 0.06, 0.06]
            },
            {
              "type": "logical",
              "attributes": {},
              "value": [false, false, false, false]
            }
          ]
        }
      ]
    }