Parse cell till its end and set content, lines_to_next_cell.
        Return the position of next cell start

def find_cell_content(self, lines):
        """Parse cell till its end and set content, lines_to_next_cell.
        Return the position of next cell start"""
        cell_end_marker, next_cell_start, explicit_eoc = self.find_cell_end(lines)

        # Metadata to dict
        cell_start = 0
        if self.cell_type == 'markdown':
            if self.markdown_marker in ['"""', "'''"]:
                # Remove the triple quotes
                if lines[0].strip() == self.markdown_marker:
                    cell_start = 1
                else:
                    lines[0] = lines[0][3:]
                if not explicit_eoc:
                    last = lines[cell_end_marker - 1]
                    lines[cell_end_marker - 1] = last[:last.rfind(self.markdown_marker)]
            if self.twenty_hash.match(self.markdown_marker):
                cell_start = 1
        else:
            self.metadata = {}

        # Cell content
        source = lines[cell_start:cell_end_marker]
        self.org_content = [line for line in source]

        if self.cell_type == 'code' and self.comment_magics:
            uncomment_magic(source, self.language or self.default_language)

        if self.cell_type == 'markdown' and source:
            if self.markdown_marker.startswith(self.comment):
                source = uncomment(source, self.comment)
            if self.rst2md:
                if rst2md:
                    source = rst2md('\n'.join(source)).splitlines()
                else:
                    raise ImportError('Could not import rst2md from sphinx_gallery.notebook')

        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