code: def find_cell_content(self, lines):
          
          cell_end_marker, next_cell_start, explicit_eoc = self.find_cell_end(lines)
  
          # Metadata to dict
          if self.start_code_re.match(lines[0]) or self.alternative_start_code_re.match(lines[0]):
              cell_start = 1
          else:
              cell_start = 0
  
          # Cell content
          source = lines[cell_start:cell_end_marker]
          self.org_content = [line for line in source]
  
          if self.cell_type != 'code' or (self.metadata and not is_active('py', self.metadata)) \
                  or (self.language is not None and self.language != self.default_language):
              source = uncomment(source, self.comment)
          elif self.metadata is not None and self.comment_magics:
              source = self.uncomment_code_and_magics(source)
  
          self.content = source
  
          self.lines_to_next_cell = count_lines_to_next_cell(
              cell_end_marker,
              next_cell_start,
              len(lines),
              explicit_eoc)
  
          return next_cell_start
docs: Parse cell till its end and set content, lines_to_next_cell.
          Return the position of next cell start