The package org.apache.lucene.queryparser.flexible.config contains query configuration handler abstract class that all config handlers should extend.
See {@link org.apache.lucene.queryparser.flexible.standard.config.StandardQueryConfigHandler} for a reference implementation.
The {@link org.apache.lucene.queryparser.flexible.core.config.QueryConfigHandler} and {@link org.apache.lucene.queryparser.flexible.core.config.FieldConfig} are used in the processors to access config information in a flexible and independent way. See {@link org.apache.lucene.queryparser.flexible.standard.processors.TermRangeQueryNodeProcessor} for a reference implementation.