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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _table_union(left, right, distinct=False):
 """ Form the table set union of two table expressions having identical schemas. Parameters right : TableExpr distinct : boolean, default False Only union distinct rows not occurring in the calling table (this can be very expensive, be careful) Returns ------- union : TableExpr """

    op = ops.Union(left, right, distinct=distinct)
    return op.to_expr()