code: public String getMarshallingType() {
          if (isList()) {
              return "LIST";
          } else if (isMap()) {
              return "MAP";
          } else if (isJsonValue()) {
              return "JSON_VALUE";
          } else if (!isSimple()) {
              return "STRUCTURED";
          } else {
              return TypeUtils.getMarshallingType(variable.getSimpleType());
          }
      }
docs: Currently used only for JSON services.
  
  @return Marshalling type to use when creating a {@link MarshallingInfo}. Must be a field of {@link
  com.amazonaws.protocol.MarshallingType}.