Normalizes glyph bottom margin.

    * **value** must be a :ref:`type-int-float` or `None`.
    * Returned value is the same type as the input value.

def normalizeGlyphBottomMargin(value):
    """
    Normalizes glyph bottom margin.

    * **value** must be a :ref:`type-int-float` or `None`.
    * Returned value is the same type as the input value.
    """
    if not isinstance(value, (int, float)) and value is not None:
        raise TypeError("Glyph bottom margin must be an "
                        ":ref:`type-int-float`, not %s."
                        % type(value).__name__)
    return value