'[*required*] The datatype of the column.  Valid values (as
defined by the spec) are:
\'boolean\', \'bit\', \'unsignedByte\', \'short\', \'int\', \'long\',
\'char\', \'unicodeChar\', \'float\', \'double\', \'floatComplex\', or
\'doubleComplex\'
Many VOTABLE files in the wild use \'string\' instead of \'char\',
so that is also a valid option, though \'string\' will always be
converted to \'char\' when writing the file back out.'

@property
def datatype(self):

    return self._datatype
