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 * modification, are permitted provided that the following conditions are
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 *
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 * notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 *
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 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 */

package io.grpc;

import javax.annotation.concurrent.ThreadSafe;

/**
 * Interface to initiate processing of incoming remote calls. Advanced applications and generated
 * code will implement this interface to allows {@link Server}s to invoke service methods.
 */
@ExperimentalApi("https://github.com/grpc/grpc-java/issues/933")
@ThreadSafe
public interface ServerCallHandler<RequestT, ResponseT> {
  /**
   * Produce a non-{@code null} listener for the incoming call. Implementations are free to call
   * methods on {@code call} before this method has returned.
   *
   * <p>If the implementation throws an exception, {@code call} will be closed with an error.
   * Implementations must not throw an exception if they started processing that may use {@code
   * call} on another thread.
   *
   * @param method descriptor for the call
   * @param call object for responding to the remote client.
   * @return listener for processing incoming request messages for {@code call}
   */
  ServerCall.Listener<RequestT> startCall(
      MethodDescriptor<RequestT, ResponseT> method,
      ServerCall<ResponseT> call,
      Metadata headers);
}
