ezsystems / ezpublish-kernel

        // Map existing relations for easier handling

        $mappedRelations = [];

        foreach ($existingRelations as $relation) {

            if ($relation->type & Relation::FIELD) {

                $fieldDefinition = $contentType->getFieldDefinition($relation->sourceFieldDefinitionIdentifier);

                if ($fieldDefinition !== null) {

                    $mappedRelations[Relation::FIELD][$fieldDefinition->id][$relation->destinationContentInfo->id] = $relation;

                }

            }

            if ($relation->type & Relation::ASSET) {

                $fieldDefinition = $contentType->getFieldDefinition($relation->sourceFieldDefinitionIdentifier);

                }

            }

            if ($relation->type & Relation::ASSET) {

                $fieldDefinition = $contentType->getFieldDefinition($relation->sourceFieldDefinitionIdentifier);

                if ($fieldDefinition !== null) {

                    $mappedRelations[Relation::ASSET][$fieldDefinition->id][$relation->destinationContentInfo->id] = $relation;

                }

            }

            // Using bitwise AND as Legacy Stack stores COMMON, LINK and EMBED relation types

            // in the same entry using bitmask