docs: @JsonIgnore
      public String getBranch() {
  
          String ref = getRef();
          if (ref == null || ref.trim().length() == 0) {
              return (null);
          }
  
          ref = ref.trim();
          int refsHeadsIndex = ref.indexOf(REFS_HEADS);
          if (refsHeadsIndex != 0) {
              return (null);
          }
  
          return (ref.substring(REFS_HEADS.length()));
      }