code: def flatten_blocks(lines, num_indents=-1):
      
      # The standard indent is four spaces
      INDENTATION = " " * 4
  
      if not lines:
          return ""
  
      # If this is a string, add the indentation and finish here
      if isinstance(lines, six.string_types):
          return INDENTATION * num_indents + lines
  
      # If this is not a string, join the lines and recurse
      return "\n".join([flatten_blocks(line, num_indents + 1) for line in lines])
docs: Take a list (block) or string (statement) and flattens it into a string
      with indentation.