'Convert the object *value* (in the native in-memory datatype)
to a unicode string suitable for serializing in the TABLEDATA_
format.
Parameters
value : native type corresponding to this converter
The value
mask : bool
If `True`, will return the string representation of a
masked value.
Returns
tabledata_repr : unicode'

def output(self, value, mask):

    raise NotImplementedError(u"This    datatype    must    implement    a    'output'    method.")
