code: def register_linter(linter):
          
          if hasattr(linter, "EXTS") and hasattr(linter, "run"):
              LintFactory.PLUGINS.append(linter)
          else:
              raise LinterException("Linter does not have 'run' method or EXTS variable!")
docs: Register a Linter class for file verification.
  
          :param linter:
          :return: