# File lib/rubigen/commands.rb, line 181
      def class_collisions(*class_names)
        class_names.flatten.each do |class_name|
          # Convert to string to allow symbol arguments.
          class_name = class_name.to_s

          # Skip empty strings.
          next if class_name.strip.empty?

          # Split the class from its module nesting.
          nesting = class_name.split('::')
          name = nesting.pop

          # Extract the last Module in the nesting.
          last = nesting.inject(Object) { |last, nest|
            break unless last.const_defined?(nest)
            last.const_get(nest)
          }

          # If the last Module exists, check whether the given
          # class exists and raise a collision if so.
          if last and last.const_defined?(name.camelize)
            raise_class_collision(class_name)
          end
        end
      end