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GraphqL Java

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package graphql.schema;

import graphql.language.Field;

import java.util.List;
import java.util.Map;
import java.util.function.Supplier;

/**
 * This allows you to retrieve the selection set of fields that have been asked for when the
 * {@link DataFetcher} was invoked.
 *
 * For example imagine we are fetching the field 'user' in the following query
 *
 *  * {@code
 *
 *  {
 *      user {
 *          name
 *          age
 *          weight
 *      }
 *  }
 * }
 * 
 *
 * The selection set in the case above consists of the fields "name, age and weight".
 *
 * You can use this selection set perhaps to "peek" ahead and decide that field values you might need
 * from the underlying data system.  Imagine a SQL system where this might represent the SQL 'projection'
 * of columns say.
 */
public interface DataFetchingFieldSelectionSet extends Supplier>> {

    /**
     * @return a map of the fields that represent the selection set
     */
    Map> get();
}