You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: observer.rb
    path of file: ./repos/glimmer/lib/glimmer/data_binding
    
    the code of the file until where you have to start completion: # Copyright (c) 2007-2024 Andy Maleh
#
# Permission i
    
      def remove_dependent(parent_to_dependent_hash)
        registration = parent_to_dependent_hash.keys.first
        dependent = parent_to_dependent_hash.values.first
        dependents_for(registration).delete(dependent).tap do
          dependents.delete([registration.object_id]) if dependents_for(registration).empty?
        end
      end