Complex function should be refactored

Reports the functions or methods that are too complex.

Complexity is evaluated based on four metrics:

• Lines of code — the number of code lines in a function/method (less is better)

• Maximum Nesting depth — the maximum number of nested statements in a function/method body (less is better)

• Cyclomatic complexity — the function/method cyclomatic complexity (less is better)

• Number of variables — the number of variables used in function/method body