'See `FITSDiff` for explanations of the initialization parameters.'

def __init__(self, a, b, ignore_fields=[], numdiffs=10, rtol=0.0, atol=0.0, tolerance=None):

    self.ignore_fields = set(ignore_fields)
    self.numdiffs = numdiffs
    self.rtol = rtol
    self.atol = atol
    if (tolerance is not None):
        warnings.warn('"tolerance"    was    deprecated    in    version    2.0    and    will    be    removed    in    a    future    version.    Use    argument    "rtol"    instead.', AstropyDeprecationWarning)
        self.rtol = tolerance
    self.common_columns = []
    self.common_column_names = set()
    self.diff_rows = ()
    self.diff_column_count = ()
    self.diff_columns = ()
    self.diff_column_attributes = []
    self.diff_column_names = ()
    self.diff_values = []
    self.diff_ratio = 0
    self.diff_total = 0
    super(TableDataDiff, self).__init__(a, b)
