code: public void clearValues(String fieldName) {
          Utils.require(!Utils.isEmpty(fieldName), "fieldName");
          m_valueMap.remove(fieldName);
          m_valueRemoveMap.remove(fieldName);
      }
docs: Clear all values for the given field. Both "add" and "remove" values, if any, are
  deleted.
  
  @param fieldName Name of a field.