code: def create_branch(self, branch_name: str):
          
          LOGGER.info('creating branch: %s', branch_name)
          self._validate_branch_name(branch_name)
          if branch_name in self.list_branches():
              LOGGER.error('branch already exists')
              sys.exit(-1)
          new_branch = self.repo.create_head(branch_name)
          new_branch.commit = self.repo.head.commit
docs: Creates a new branch
  
          Args:
              branch_name: name of the branch