code: def error_leader(self, infile=None, lineno=None):
          "Emit a C-compiler-like, Emacs-friendly error-message leader."
          if infile is None:
              infile = self.infile
          if lineno is None:
              lineno = self.lineno
          return "\"%s\", line %d: " % (infile, linenof error_leader(self, infile=None, lineno=None):
          "Emit a C-compiler-like, Emacs-friendly error-message leader."
          if infile is None:
              infile = self.infile
          if lineno is None:
              lineno = self.lineno
          return "\"%s\", line %d: " % (infile, lineno)
docs: Emit a C-compiler-like, Emacs-friendly error-message leader.