content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.arrow.flight.auth2;
  
  import org.apache.arrow.flight.CallHeaders;
  import org.apache.arrow.flight.grpc.CredentialCallOption;
  
  /** Interface for client side header parsing and conversion to CredentialCallOption. */
  public interface ClientHeaderHandler {
    /**
     * Parses the incoming headers and converts them into a CredentialCallOption.
     *
     * @param incomingHeaders Incoming headers to parse.
     * @return An instance of CredentialCallOption.
     */
    CredentialCallOption getCredentialCallOptionFromIncomingHeaders(CallHeaders incomingHeaders);
  
    /** An client header handler that does nothing. */
    ClientHeaderHandler NO_OP =
        new ClientHeaderHandler() {
          @Override
          public CredentialCallOption getCredentialCallOptionFromIncomingHeaders(
              CallHeaders incomingHeaders) {
            return null;
          }
        };
  }
  