code: public boolean hasMandatoryChildNodeDefinitions( Name primaryType,
                                                       Set<Name> mixinTypes ) {
          if (mandatoryChildrenNodeTypes.containsKey(primaryType)) return true;
          for (Name mixinType : mixinTypes) {
              if (mandatoryChildrenNodeTypes.containsKey(mixinType)) return true;
          }
          return false;
      }
docs: Determine if the named primary node type or mixin types has at least one mandatory child node definitions declared on it or
  any of its supertypes.
  
  @param primaryType the primary type name; may not be null
  @param mixinTypes the mixin type names; may not be null but may be empty
  @return true if any of the the named node types has one or more mandatory child node definitions, or false if there are
  none