This cluster is currently following a code driven approach.

This means that the Accessors for the attribute MeasuredValue are no longer available.

Now to set the value for this attribute the following code change applies:

BEFORE (using the Accessors)

app::Clusters::IlluminanceMeasurement::Attributes::MeasuredValue::Set(1, static_cast<uint16_t>(1000));

CURRENT (using the code driven approach)

CHIP_ERROR err = app::Clusters::IlluminanceMeasurement::SetMeasuredValue(1, static_cast<uint16_t>(1000));
if (err == CHIP_NO_ERROR)
{
    // SetMeasuredValue() succeeded
}
else
{
    // SetMeasuredValue() failed
}