def _fill(self, size):
        """fills the internal buffer from the source iterator"""
        try:
            for i in range(size):
                self.buffer.append(self.source.next())
        except __HOLE__:
            self.buffer.append((EndOfFile, EndOfFile))
        self.len = len(self.buffer)
dataset/ETHPy150Open brehaut/picoparse/picoparse/__init__.py/BufferWalker._fill