public static <T> T newClient(SessionProtocol protocol, EndpointGroup endpointGroup, Class<T> clientType) {
        return builder(protocol, endpointGroup).build(clientType);
    }
Creates a new gRPC client that connects to the specified {@link EndpointGroup} with
the specified {@link SessionProtocol} and {@link GrpcSerializationFormats#PROTO} using the default
{@link ClientFactory}.

@param protocol the {@link SessionProtocol}
@param endpointGroup the server {@link EndpointGroup}
@param clientType the type of the new gRPC client

@throws IllegalArgumentException if the {@code clientType} is an unsupported gRPC client stub.
grpc/src/main/java/com/linecorp/armeria/client/grpc/GrpcClients.java