code: void checkout(File project, String branch) {
  		try {
  			String currentBranch = currentBranch(project);
  			if (currentBranch.equals(branch)) {
  				log.info("Won't check out the same branch. Skipping");
  				return;
  			}
  			log.info("Checking out branch [" + branch + "]");
  			checkoutBranch(project, branch);
  			log.info("Successfully checked out the branch [" + branch + "]");
  		}
  		catch (Exception e) {
  			throw new IllegalStateException(e);
  		}
  	}
docs: Checks out a branch for a project.
  @param project - a Git project
  @param branch - branch to check out