code: def isin(arg, values):
      
      op = ops.Contains(arg, values)
      return op.to_expr()
docs: Check whether the value expression is contained within the indicated
      list of values.
  
      Parameters
      ----------
      values : list, tuple, or array expression
        The values can be scalar or array-like. Each of them must be
        comparable with the calling expression, or None (NULL).
  
      Examples
      --------
      >>> import ibis
      >>> table = ibis.table([('string_col', 'string')])
      >>> table2 = ibis.table([('other_string_col', 'string')])
      >>> expr = table.string_col.isin(['foo', 'bar', 'baz'])
      >>> expr2 = table.string_col.isin(table2.other_string_col)
  
      Returns
      -------
      contains : BooleanValue