code: @Deprecated
      public List<GraphQLObjectType> findImplementations(GraphQLSchema schema, GraphQLInterfaceType interfaceType) {
          List<GraphQLObjectType> result = new ArrayList<>();
          for (GraphQLType type : schema.getAllTypesAsList()) {
              if (!(type instanceof GraphQLObjectType)) {
                  continue;
              }
              GraphQLObjectType objectType = (GraphQLObjectType) type;
              if ((objectType).getInterfaces().contains(interfaceType)) {
                  result.add(objectType);
              }
          }
          return result;
      }
docs: This method is deprecated due to a performance concern.
  
  The Algorithm complexity: O(n^2), where n is number of registered GraphQLTypes
  
  That indexing operation is performed twice per input document:
  1. during validation
  2. during execution
  
  We now indexed all types at the schema creation, which has brought complexity down to O(1)
  
  @param schema        GraphQL schema
  @param interfaceType an interface type to find implementations for
  
  @return List of object types implementing provided interface
  
  @deprecated use {@link graphql.schema.GraphQLSchema#getImplementations(GraphQLInterfaceType)} instead