How to recover the original document from an ast.Node of Block type?

[furoxr]

Hello all~ I'm trying to recover the original document from a block level ast.Node. But I met some issues here:

1. At the phase of parsing block, the info of blank lines is not stored, so I can't get how many blank lines in, before or after the block.
2. In the quote block, the blank lines are also trimed and the info is not included in the node.

Is there a way to keep those info during parsing, do I have to reimplement the phase of parsing blocks?