code: public static FieldTextBuilder from(final FieldText fieldText) {
          return (fieldText instanceof FieldTextBuilder)
              ? (FieldTextBuilder)fieldText
              : new FieldTextBuilder(fieldText);
      }
docs: Converts a {@link FieldText} object into a {@code FieldTextBuilder}. This method can be more efficient than using
  the equivalent constructor but the returned object might be backed by the {@link FieldText} object provided.
  
  @param fieldText The fieldtext expression to convert
  @return An equivalent instance of {@code FieldTextBuilder}