code: def _set_line_indent(src, line, indent):
      '''
      Indent the line with the source line.
      '''
      if not indent:
          return line
  
      idt = []
      for c in src:
          if c not in ['\t', ' ']:
              break
          idt.append(c)
  
      return ''.join(idt) + line.lstrip(f _set_line_indent(src, line, indent):
      '''
      Indent the line with the source line.
      '''
      if not indent:
          return line
  
      idt = []
      for c in src:
          if c not in ['\t', ' ']:
              break
          idt.append(c)
  
      return ''.join(idt) + line.lstrip()
docs: Indent the line with the source line.