':param \*columns:
A sequence of column names or Column objects.
:param name:
Optional, the in-database name of this constraint.
:param deferrable:
Optional bool.  If set, emit DEFERRABLE or NOT DEFERRABLE when
issuing DDL for this constraint.
:param initially:
Optional string.  If set, emit INITIALLY <value> when issuing DDL
for this constraint.
:param \**kw: other keyword arguments including dialect-specific
arguments are propagated to the :class:`.Constraint` superclass.'

def __init__(self, *columns, **kw):

    Constraint.__init__(self, **kw)
    ColumnCollectionMixin.__init__(self, *columns)
