public static MethodDescriptor getMethodDescriptor(final String methodName,
    final ServiceDescriptor serviceDesc) throws UnknownProtocolException {
    MethodDescriptor methodDesc = serviceDesc.findMethodByName(methodName);
    if (methodDesc == null) {
      throw new UnknownProtocolException(
        "Unknown method " + methodName + " called on service " + serviceDesc.getFullName());
    }
    return methodDesc;
  }
Returns the name to use for coprocessor service calls. For core HBase services (in the hbase.pb
protobuf package), this returns the unqualified name in order to provide backward compatibility
across the package name change. For all other services, the fully-qualified service name is
used.
hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/CoprocessorRpcUtils.java