Return expression which is the disjunction of `expr1` and `expr2`.

def Disjunction(expr1: Expression, expr2: Expression) -> Expression:
    """Return expression which is the disjunction of `expr1` and `expr2`."""
    expr = Expression(ast.BoolOp(ast.Or(), [expr1.body, expr2.body]))
    return ast.fix_missing_locations(expr)