code: public static String getFieldName(
        Descriptors.FieldDescriptor field, boolean capitializeFirstLetter) {
      String fieldName = field.getName();
      if (SPECIAL_CASES.containsKey(fieldName)) {
        String output = SPECIAL_CASES.get(fieldName);
        if (capitializeFirstLetter) {
          return output;
        } else {
          return ((char) (output.charAt(0) + ('a' - 'A'))) + output.substring(1);
        }
      }
      return underscoresToCamelCase(fieldName, capitializeFirstLetter);
    }
docs: Returns the Java name for a proto field.