code: public com.google.api.ads.admanager.axis.v201805.BaseCustomFieldValue[] getCustomFieldValues() {
          return customFieldValues;
      }
docs: Gets the customFieldValues value for this ProposalLineItem.
  
  @return customFieldValues   * The values of the custom fields associated with the {@code
  ProposalLineItem}.
  This attribute is optional.
  This attribute can be configured as editable after
  the proposal has been submitted.
  Please check with your network administrator for editable
  fields configuration.