anchor.diff:          pbx_variant_group_section?
           xc_build_configuration_section
           xc_configuration_list_section
  +        xc_remote_swift_package_reference_section?
  +        xc_swift_package_product_dependency_section?
           xc_version_group_section?
         '}' ';'
       ;
  
positive.code:       '}' ';'
      ;
  
  xc_version_group
      : REFERENCE '=' '{'
          isa_xc_version_group
  
negative.code:     : ISA '=' 'XCConfigurationList' ';'
      ;
  
  isa_xc_remote_swift_package_reference
      : ISA '=' 'XCRemoteSwiftPackageReference' ';'
      ;
  
  isa_xc_swift_package_product_dependency
      : ISA '=' 'XCSwiftPackageProductDependency' ';'
      ;
  
  isa_xc_version_group
      : ISA '=' 'XCVersionGroup' ';'
      ;
  