def _indent(self, textstr, indent_level=4):
        """
        Indent a string.

        Textwrap's indent method only exists for 3.3 or above.  In 2.7 we have
        to fake it.

        Parameters
        ----------
        textstring : str
            String to be indented.
        indent_level : str
            Number of spaces of indentation to add.

        Returns
        -------
        str
            Possibly multi-line string indented by the specified amount.
        """
        if sys.hexversion >= 0x03030000:
            return textwrap.indent(textstr, ' ' * indent_level)
        else:
            lst = [(' ' * indent_level + x) for x in textstr.split('\n')]
            return '\n'.join(lst)
Indent a string.

        Textwrap's indent method only exists for 3.3 or above.  In 2.7 we have
        to fake it.

        Parameters
        ----------
        textstring : str
            String to be indented.
        indent_level : str
            Number of spaces of indentation to add.

        Returns
        -------
        str
            Possibly multi-line string indented by the specified amount.