'Default visitor for tree leaves.
A tree leaf is always just gets appended to the current unwrapped line.
Arguments:
leaf: the leaf to visit.'

def DefaultLeafVisit(self, leaf):

    if (leaf.type in _WHITESPACE_TOKENS):
        self._StartNewLine()
    elif ((leaf.type != grammar_token.COMMENT) or leaf.value.strip()):
        if (leaf.value == ';'):
            self._StartNewLine()
        else:
            self._cur_unwrapped_line.AppendNode(leaf)
