code: private static PBXObjectRef createPBXBuildFile(final PBXObjectRef fileRef, final Map settings) {
      final Map map = new HashMap();
      map.put("fileRef", fileRef);
      map.put("isa", "PBXBuildFile");
      if (settings != null) {
        map.put("settings", settings);
      }
      return new PBXObjectRef(map);
    }
docs: Create PBXBuildFile.
  
  @param fileRef
  source file.
  @param settings
  build settings.
  @return PBXBuildFile.