'Return an indented block and info.
Extract an indented block where the indent is known for the first line
and unknown for all other lines.
:Parameters:
- `indent`: The first line\'s indent (# of columns/characters).
- `until_blank`: Stop collecting at the first blank line if true
(1).
- `strip_indent`: Strip `indent` characters of indentation if true
(1, default).
- `strip_top`: Strip blank lines from the beginning of the block.
:Return:
- the indented block,
- its indent,
- its first line offset from BOF, and
- whether or not it finished with a blank line.'

def get_first_known_indented(self, indent, until_blank=0, strip_indent=1, strip_top=1):

    offset = self.abs_line_offset()
    (indented, indent, blank_finish) = self.input_lines.get_indented(self.line_offset, until_blank, strip_indent, first_indent=indent)
    self.next_line((len(indented) - 1))
    if strip_top:
        while (indented and (not indented[0].strip())):
            indented.trim_start()
            offset += 1
    return (indented, indent, offset, blank_finish)
