COBCH1639 必須のパラメーターはオプションのパラメーターの前に指定する必要がある

An optional parameter has been specified before a required parameter in the declaration of a method.

Specify any required parameters before you specify optional parameters in the signature. In the following example, specify p2 before p1.

class-id myClass.
method-id myMethod.
procedure division using by value p1 as string = "Hello", p2 as string.
...
end method.
end class.