code: public void validate() {
      Errors errors = new Errors();
      for (TypeMap<?, ?> typeMap : getTypeMaps()) {
        try {
          typeMap.validate();
        } catch (ValidationException e) {
          errors.merge(e.getErrorMessages());
        }
      }
  
      errors.throwValidationExceptionIfErrorsExist();
    }
docs: Validates that <b>every</b> top level destination property for each configured TypeMap is
  mapped to one and only one source property, or that a {@code Converter} was
  {@link TypeMap#setConverter(Converter) set} for the TypeMap. If not, a ConfigurationException
  is thrown detailing any missing mappings.
  
  @throws ValidationException if any TypeMaps contain unmapped properties