Methods Implementation

`ARG`	Returns a pointer to a method argument.
`BEGIN_METHOD`	Begins the implementation of a method that takes at least one argument.
`BEGIN_METHOD_VOID`	Begins the implementation of a method that takes no argument.
`END_METHOD`	Ends the implementation of a method.
`GB.NParam`	Returns the number of variable arguments of a method.
`LENGTH`	Returns the length of a string method argument.
`MISSING`	Returns if an optional argument has a value.
`STRING`	Returns the address of a string method argument.
`VARG`	Returns the value of a method argument.
`VARGOPT`	Returns the value of an optional method argument.