Create free row in JS step in Pentaho Data Integrator

function outputResult(outData) {
  var row = createRowCopy(rmi.size());
  for ( var uCol in outData) {
    var valIdx = rmi.indexOfValue(uCol);
    if (valIdx >= 0) {
      row[valIdx] = outData[uCol];
    }
  }
  putRow(row);
}

//Script here
var rmi = getOutputRowMeta()
rmi.clear()
var field = new org.pentaho.di.core.row.ValueMeta("FILE_URL", org.pentaho.di.core.row.ValueMetaInterface.TYPE_NUMBER)
rmi.addValueMeta(field)
field = new org.pentaho.di.core.row.ValueMeta("FILE_WILDCARD", org.pentaho.di.core.row.ValueMetaInterface.TYPE_STRING)
rmi.addValueMeta(field)

field = new org.pentaho.di.core.row.ValueMeta("FILEJSON", org.pentaho.di.core.row.ValueMetaInterface.TYPE_STRING)
rmi.addValueMeta(field)


outputResult({
  FILE_URL: 123,
  FILE_WILDCARD: "privet",
})

outputResult({
  FILE_URL: 123,
  FILE_WILDCARD: "privet",
  FILEJSON: "another string"
})


trans_Status = SKIP_TRANSFORMATION;