'Return an indented block and info.
Extract an indented block where the indent is known for all lines.
Starting with the current line, extract the entire text block with at
least `indent` indentation (which must be whitespace, except for the
first line).
:Parameters:
- `indent`: The number of indent 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).
:Return:
- the indented block,
- its first line offset from BOF, and
- whether or not it finished with a blank line.'

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

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