code: def get_commit(self, commit_id, repository_id, project=None, change_count=None):
          
          route_values = {}
          if project is not None:
              route_values['project'] = self._serialize.url('project', project, 'str')
          if commit_id is not None:
              route_values['commitId'] = self._serialize.url('commit_id', commit_id, 'str')
          if repository_id is not None:
              route_values['repositoryId'] = self._serialize.url('repository_id', repository_id, 'str')
          query_parameters = {}
          if change_count is not None:
              query_parameters['changeCount'] = self._serialize.query('change_count', change_count, 'int')
          response = self._send(http_method='GET',
                                location_id='c2570c3b-5b3f-41b8-98bf-5407bfde8d58',
                                version='5.1-preview.1',
                                route_values=route_values,
                                query_parameters=query_parameters)
          return self._deserialize('GitCommit', response)
docs: GetCommit.
          [Preview API] Retrieve a particular commit.
          :param str commit_id: The id of the commit.
          :param str repository_id: The id or friendly name of the repository. To use the friendly name, projectId must also be specified.
          :param str project: Project ID or project name
          :param int change_count: The number of changes to include in the result.
          :rtype: :class:`<GitCommit> <azure.devops.v5_1.git.models.GitCommit>`