code: VariableDescriptor getVariableDescriptor(String name, String signature) {
          VariableDescriptor variableDescriptor = scannerContext.getStore().create(VariableDescriptor.class);
          variableDescriptor.setName(name);
          variableDescriptor.setSignature(signature);
          return variableDescriptor;
      }
docs: Return the field descriptor for the given type and field signature.
  
  @param name
  The variable name.
  @param signature
  The variable signature.
  @return The field descriptor.