def to_s(prefix = nil)
      include_lines = includes.map { |path| "#include \"#{normalized_xcconfig_path(path)}\"" }
      settings = to_hash(prefix).sort_by(&:first).map { |k, v| "#{k} = #{v}".strip }
      (include_lines + settings).join("\n") << "\n"
    end
def to_s(prefix = nil)
      include_lines = includes.map { |path| "#include \"#{normalized_xcconfig_path(path)}\"" }
      settings = to_hash(prefix).sort_by(&:first).map { |k, v| "#{k} = #{v}".strip }
      (include_lines + settings).join("\n") << "\n"
    end
@!group Serialization
-------------------------------------------------------------------------
 Sorts the internal data by setting name and serializes it in the xcconfig
 format.

 @example

   config = Config.new('PODS_ROOT' => '"$(SRCROOT)/Pods"', 'OTHER_LDFLAGS' => '-lxml2')
   config.to_s # => "OTHER_LDFLAGS = -lxml2\nPODS_ROOT = \"$(SRCROOT)/Pods\""

 @return [String] The serialized internal data.