code: public static StructuredType checkIsStructuredType(Type type) {
          if (!isStructuredType(type)) {
              throw new ODataSystemException("A structured type is required, but '" + type.getFullyQualifiedName() +
                      "' is not a structured type: " + type.getMetaType());
          }
          return (StructuredType) type;
      }
docs: Checks if the specified OData type is a structured type and throws an exception if it is not.
  
  @param type The OData type.
  @return The OData type.
  @throws ODataSystemException If the OData type is not a structured type.