public boolean isMissingValue(Object value){
  if (value instanceof Double) {
    double doubleValue=(Double)value;
    return Double.isNaN(doubleValue);
  }
  return false;
}

public boolean isMissingValue ( Object value ) { if ( value instanceof Double ) { double doubleValue = ( Double ) value ; return Double . isNaN ( doubleValue ) ; } return false ; }
determines whether the argument is equal to the missing value marker .
