[X++] SysExtension Attribute name of parm method

If you are using the SysExtensionFramework introduced with Dynamics AX 2012 and creating a new attribute class derived from SysAttribute, you have to name the parm-method(s) of your new attribute class like your parameter in the new-method!
Otherwise you will have a bad time figuring out that the following line checks this in standard:
Line 16 checks if the parm method with name format 'parm' + [nameOfParameter] is present.


class MyNewAttribute extends SysAttribute
    ClassId     locClassId;

Note the name of the parameter matches the name of the parm method!

public void new(ClassId _locClassId)
public ClassId parmLocClassId(ClassId _locClassId = locClassId)
    locClassId = _locClassId;

    return locClassId;

I hope to save you the 10 minutes of time and the nerves I spent on figuring this out.