code: def line_is_executable(line: str) -> bool:
      
  
      if line_is_comment(line):
          return False
  
      if re.match(RE_TYPE_NAMES, line):
          return False
  
      for exp in EXECUTABLE_CODE_START:
          if re.match(exp, line) != None:
              return True
  
      return False
docs: line_is_executable() returns True iff the line can start an
         executable statement in a program.