Ros- resolve error "tf2\u buffer\was not declared in this scope"

Problem description ：
Use ros melodic edition compiler , The following error is reported ：
error: ‘tf2_buffer_’ was not declared in this scope
inline tf2_ros::Buffer& getBuffer() { return tf2_buffer_; }
^~~~~~~~~~~
resolvent ：
Inquiry , Found to be ros melodic The version has modified this place , Different from the previous version , use tf2_buffer_ptr_ Replaced the tf2_buffer_ , So the program needs to be modified .
Reference resources ：Compile Error Melodic due to tf change

		// The original way of writing ：
		inline tf2_ros::Buffer& getBuffer() {
     return tf2_buffer_; }
		// It is amended as follows ：
		inline std::shared_ptr<tf2_ros::Buffer> &getBuffer() {
    return tf2_buffer_ptr_;}