code_call_lens: raising the developer awareness of critical code

As a developer, it is often complex to foresee the impact of changes in source code on usage, e.g., it is time-consuming to find out all components that will be impacted by a change or estimate the impact on the usability of a failing piece of code. It is therefore hard to decide how much effort in quality assurance is justifiable to obtain the desired business goals. In this paper, to reduce the difficulty for developers to understand the importance of source code, we propose an automated way to provide this information to developers as they are working on a given piece of code. As a proof-of-concept, we developed a plug-in for Microsoft Visual Studio Code that informs about the importance of source code methods based on the frequency of usage by the end-users of the developed software. The plug-in aims to increase the awareness developers have about the importance of source code in an unobtrusive way, helping them to prioritize their effort to quality assurance, technical excellence, and usability. code_call_lens can be downloaded from GitHub at https://github.com/xxMUROxx/vscode.code_call_lens.