old_contents: from tailor.swift.swiftlistener import SwiftListener
  from tailor.utils.charformat import isUpperCamelCase
  
  
  class MainListener(SwiftListener):
  
      def enterClassName(self, ctx):
          className = ctx.getText()
          if not isUpperCamelCase(className):
              print('Line', str(ctx.start.line) + ':', 'Class names should be in UpperCamelCase')
  
      def enterEnumName(self, ctx):
          pass
  
      def enterEnumCaseName(self, ctx):
          pass
  
      def exitStructName(self, ctx):
          pass
  
new_contents: from tailor.swift.swiftlistener import SwiftListener
  from tailor.utils.charformat import isUpperCamelCase
  
  
  class MainListener(SwiftListener):
  
      def enterClassName(self, ctx):
          self.__verify_upper_camel_case(ctx, 'Class names should be in UpperCamelCase')
  
      def enterEnumName(self, ctx):
          pass
  
      def enterEnumCaseName(self, ctx):
          pass
  
      def enterStructName(self, ctx):
          pass
  
      @staticmethod
      def __verify_upper_camel_case(ctx, err_msg):
          construct_name = ctx.getText()
          if not isUpperCamelCase(construct_name):
              print('Line', str(ctx.start.line) + ':', err_msg)
  
subject: Add method to handle UpperCamelCase verification