def METHOD_NAME(self):
    # first loop to calculate number of rows
    lengths = n.zeros(len(self.files), dtype=int)
    for i, file in enumerate(self.files):
        try:
            lengths[i] = len(file.getNode(self.path))
        except tables.NoSuchNodeError:
            print("WARN: node %s does not exist in file %s" % (self.path, file.filename))
            lengths[i] = 0
    # create result array ...
    result = n.zeros(lengths.sum(), dtype=self._v_dtype)
    # .. and fill it
    for i, file in enumerate(self.files):
        if lengths[i] == 0:
            continue
        result[lengths[:i].sum():lengths[:i].sum()+lengths[i]] = file.getNode(self.path).METHOD_NAME()
    return result