code: function(formats) {
          for(let format of formats) {
              // TODO: rather than hard coding the mime type use library.spec.base_mime_type
              if(format.mime_type.match(/application\/tsrc\+.+/)) {
                  return format;
              }
          }
          return null;
      }
docs: Returns the first resource container format found in the list.
  E.g. the array may contain binary formats such as pdf, mp3, etc. This basically filters those.
  
  @param formats {[]} an array of resource formats
  @returns {{}} the resource container format