parameters: (expr)
docstring: Support our syntax for emphasizing certain lines of code.
  
      expr should be like '1 2' to emphasize lines 1 and 2 of a code block.
      Returns a list of ints, the line numbers to emphasize.
docstring_summary: Support our syntax for emphasizing certain lines of code.
docstring_tokens: Support our syntax for emphasizing certain lines of code .
function: def parse_hl_lines(expr):
      """Support our syntax for emphasizing certain lines of code.
  
      expr should be like '1 2' to emphasize lines 1 and 2 of a code block.
      Returns a list of ints, the line numbers to emphasize.
      """
      if not expr:
          return []
  
      try:
          return list(map(int, expr.split()))
      except ValueError:
          return []
function_tokens: def parse_hl_lines ( expr ) : if not expr : return [ ] try : return list ( map ( int , expr . split ( ) ) ) except ValueError : return [ ]