code: public boolean isSubType(String typeName) throws AtlasException {
          HierarchicalType cType = typeSystem.getDataType(HierarchicalType.class, typeName);
          return (cType == this || cType.superTypePaths.containsKey(getName()));
      }
docs: Given type must be a SubType of this type.
  @param typeName
  @throws AtlasException