public void addField(PdxField ft) {
    if (fieldsMap.put(ft.getFieldName(), ft) != null) {
      throw new PdxFieldAlreadyExistsException(
          "The field \"" + ft.getFieldName() + "\" already exists.");
    }
    fields.add(ft);
  }
Return true if two pdx types have same class name and the same fields but, unlike equals, field
order does not matter. Note a type that expects a domain class can be compatible with one that
does not expect a domain class.

@param other the other pdx type
@return true if two pdx types are compatible.
geode-core/src/main/java/org/apache/geode/pdx/internal/PdxType.java