docs: public FieldDescriptorDef getField(String name)
      {
          FieldDescriptorDef fieldDef = null;
  
          for (Iterator it = _fields.iterator(); it.hasNext(); )
          {
              fieldDef = (FieldDescriptorDef)it.next();
              if (fieldDef.getName().equals(name))
              {
                  return fieldDef;
              }
          }
          return null;
      }