if (!.Call(`_rxode2_isIntel`)) {
  test_that("noop has identical mu-ref", {
    pheno <- function() {
      ini({
        tcl <- log(0.008)
        tv <-  log(0.6)
        eta.cl + eta.v ~ c(1,
                           0.01, 1)
        add.err <- 0.1
      })
      model({
        cl <- exp(tcl + eta.cl) # individual value of clearance
        v <- exp(tv + eta.v)    # individual value of volume
        ke <- cl / v            # elimination rate constant
        d/dt(A1) = - ke * A1    # model differential equation
        cp = A1 / v             # concentration in plasma
        cp ~ add(add.err)  # define error model
      })
    }

    p1 <- rxode2(pheno)

    pheno2 <- function() {
      ini({
        tcl <- log(0.008)
        tv <-  log(0.6)
        eta.cl + eta.v ~ c(1,
                           0.01, 1)
        add.err <- 0.1
      })
      model({
        cl <- exp(+tcl + eta.cl) # individual value of clearance
        v <- exp(tv + eta.v)    # individual value of volume
        ke <- cl / v            # elimination rate constant
        d/dt(A1) = - ke * A1    # model differential equation
        cp = A1 / v             # concentration in plasma
        cp ~ add(add.err)  # define error model
      })
    }

    p2 <- rxode2(pheno2)

    expect_equal(p1$muRefCovariateDataFrame, p2$muRefCovariateDataFrame)
    expect_equal(p1$muRefCovariateEmpty, p2$muRefCovariateEmpty)
    expect_equal(p1$muRefCurEval, p2$muRefCurEval)
    expect_equal(p1$muRefDataFrame, p2$muRefDataFrame)
    expect_equal(p1$muRefDropParameters, p2$muRefDropParameters)
    expect_equal(p1$muRefExtra, p2$muRefExtra)
    expect_equal(p1$muRefExtraEmpty, p2$muRefExtraEmpty)
    expect_equal(p1$nonMuEtas, p2$nonMuEtas)
  })
}