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, self.explicit_eoc = self.find_cell_end(lines)

        # Metadata to dict
        if self.metadata is None:
            cell_start = 0
            self.metadata = {}
        else:
            cell_start = 1

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

        # Exactly two empty lines at the end of cell (caused by PEP8)?
        if self.ext == '.py' and self.explicit_eoc:
            if last_two_lines_blank(source):
                source = source[:-2]
                lines_to_end_of_cell_marker = 2
            else:
                lines_to_end_of_cell_marker = 0

            pep8_lines = pep8_lines_between_cells(source, lines[cell_end_marker:], self.ext)
            if lines_to_end_of_cell_marker != (0 if pep8_lines == 1 else 2):
                self.metadata['lines_to_end_of_cell_marker'] = lines_to_end_of_cell_marker

        if not is_active(self.ext, self.metadata) or \
                ('active' not in self.metadata and self.language and self.language != self.default_language):
            self.content = uncomment(source, self.comment if self.ext not in ['.r', '.R'] else '#')
        else:
            self.content = self.uncomment_code_and_magics(source)

        # Is this a raw cell?
        if ('active' in self.metadata and not is_active('ipynb', self.metadata)) or \
                (self.ext == '.md' and self.cell_type == 'code' and self.language is None):
            if self.metadata.get('active') == '':
                del self.metadata['active']
            self.cell_type = 'raw'

        # Explicit end of cell marker?
        if (next_cell_start + 1 < len(lines) and
                _BLANK_LINE.match(lines[next_cell_start]) and
                not _BLANK_LINE.match(lines[next_cell_start + 1])):
            next_cell_start += 1
        elif (self.explicit_eoc and next_cell_start + 2 < len(lines) and
              _BLANK_LINE.match(lines[next_cell_start]) and
              _BLANK_LINE.match(lines[next_cell_start + 1]) and
              not _BLANK_LINE.match(lines[next_cell_start + 2])):
            next_cell_start += 2

        self.lines_to_next_cell = count_lines_to_next_cell(
            cell_end_marker,
            next_cell_start,
            len(lines),
            self.explicit_eoc)

        return next_cell_start