def arcs(self) -> set[TArc]:
        """Get information about the arcs available in the code.

        Returns a set of line number pairs.  Line numbers have been normalized
        to the first line of multi-line statements.

        """
        if self._all_arcs is None:
            self._analyze_ast()
        assert self._all_arcs is not None
        return self._all_arcs
Get information about the arcs available in the code.

        Returns a set of line number pairs.  Line numbers have been normalized
        to the first line of multi-line statements.

        
coverage/parser.py