class Gem::Dependency

def required_by
  @required_by ||= []
end

def requirement
  version_requirements
end

def to_lock
  out = "  #{name}"
  unless requirement == Gem::Requirement.default
    out << " (#{requirement.to_s})"
  end
  out
end

def to_yaml_properties
  instance_variables.reject { |p| ["@source", "@groups"].include?(p.to_s) }
end