PyParameter.isSelf(); highlight first argument of @classmethod as self (PY-6881)

python/psi-api/src/com/jetbrains/python/psi/PyParameter.java

@@ -26,4 +26,10 @@ public interface PyParameter extends PyElement {
   PyExpression getDefaultValue();
 
   boolean hasDefaultValue();
+
+  /**
+   * @return true if the parameter is the 'self' parameter of an instance attribute function or a function
+   * annotated with @classmethod
+   */
+  boolean isSelf();
 }