code: def source_files(mongodb_path):
      
      for root, dirs, files in os.walk(mongodb_path):
          for filename in files:
              # skip files in dbtests folder
              if 'dbtests' in root:
                  continue
              if filename.endswith(('.cpp', '.c', '.h')):
                  yield os.path.join(root, filename)
docs: Find source files.