code: public boolean hasValue(String fieldName) {
  		return resultMap.containsKey(fieldName) && resultMap.get(fieldName) != null;
  	}
docs: Checks that a field exists and contains a non-null value.
  @param fieldName the name of the field to check existence/value of.
  @return true if the field exists in the result set and has a non-null value; false otherwise.