code: public GitBranchResponse renameBranch(File repositoryPath, boolean forceRename, Ref newName) 
        throws IOException, JavaGitException {
      CheckUtilities.checkNullArgument(repositoryPath, "repository path");
      CheckUtilities.checkNullArgument(newName, "new name");
      CheckUtilities.validateArgumentRefType(newName, Ref.RefType.BRANCH, "new name");
  
      IClient client = ClientManager.getInstance().getPreferredClient();
      IGitBranch gitBranch = client.getGitBranchInstance();
      return gitBranch.renameBranch(repositoryPath, forceRename, newName);
    }
docs: Renames the current branch to new branch.
  
  @param repositoryPath
  A <code>File</code> instance for the path to the repository. If null is passed,
  a <code>NullPointerException</code> will be thrown.
  @param forceRename
  True if force rename option -M should be used. False if -m should be used.
  @param newName
  When renaming the current branch to a new branch name, this is the new branch name.
  @return The result of the git branch with -m option.
  @throws IOException
  There are many reasons for which an <code>IOException</code> may be thrown.
  Examples include:
  <ul>
  <li>a directory doesn't exist</li>
  <li>access to a file is denied</li>
  <li>a command is not found on the PATH</li>
  </ul>
  @throws JavaGitException
  Thrown when there is an error executing git-branch.