parameters: (clean_lines, linenum)
return_statement: return ('', -1)
docstring: Return the most recent non-blank line and its line number.
  
    Args:
      clean_lines: A CleansedLines instance containing the file contents.
      linenum: The number of the line to check.
  
    Returns:
      A tuple with two elements.  The first element is the contents of the last
      non-blank line before the current line, or the empty string if this is the
      first non-blank line.  The second is the line number of that line, or -1
      if this is the first non-blank line.
docstring_summary: Return the most recent non-blank line and its line number.
docstring_tokens: Return the most recent non - blank line and its line number .
function: def GetPreviousNonBlankLine(clean_lines, linenum):
    """Return the most recent non-blank line and its line number.
  
    Args:
      clean_lines: A CleansedLines instance containing the file contents.
      linenum: The number of the line to check.
  
    Returns:
      A tuple with two elements.  The first element is the contents of the last
      non-blank line before the current line, or the empty string if this is the
      first non-blank line.  The second is the line number of that line, or -1
      if this is the first non-blank line.
    """
  
    prevlinenum = linenum - 1
    while prevlinenum >= 0:
      prevline = clean_lines.elided[prevlinenum]
      if not IsBlankLine(prevline):     # if not a blank line...
        return (prevline, prevlinenum)
      prevlinenum -= 1
    return ('', -1)
function_tokens: def GetPreviousNonBlankLine ( clean_lines , linenum ) : prevlinenum = linenum - 1 while prevlinenum >= 0 : prevline = clean_lines . elided [ prevlinenum ] if not IsBlankLine ( prevline ) : # if not a blank line... return ( prevline , prevlinenum ) prevlinenum -= 1 return ( '' , - 1 )