getTypeDescriptor() The type descriptor for a method node is a string containing the name of the method, its return type,
and its parameter types in a canonical form.
The type descriptor for a method node is a string containing the name of the method, its return type,
and its parameter types in a canonical form. For simplicity, I'm using the format of a Java declaration
without parameter names, and with $dynamic as the type for any dynamically typed values.