COBCH1662 Can only specify a single expression without a local variable definition

When using the PERFORM USING statement, multiple operands can be specified provided they are specified as locals within the statement (using AS syntax). If the PERFORM USING references an item that is already declared, then only one such operand is allowed.

class-id a.
method-id m.
01 d2 type System.IDisposable.
  perform using d1 as type System.IDisposable = null d2
        continue
  end-perform.
end method.
end class.