public boolean isKeepAliveWithoutCalls() {
        return this.keepAliveWithoutCalls == null ? DEFAULT_KEEP_ALIVE_WITHOUT_CALLS : this.keepAliveWithoutCalls;
    }
Gets whether keepAlive will be performed when there are no outstanding RPC on a connection.

@return True, if keepAlives should be performed even when there are no RPCs. False otherwise.

@see #setKeepAliveWithoutCalls(Boolean)
grpc-client-spring-boot-starter/src/main/java/net/devh/boot/grpc/client/config/GrpcChannelProperties.java