@staticmethod
def _inches(length, units='mm'):
    """Convert measurements to inches
        
        Inputs:
        
            * length (scalar) - dimension to be converted into units
            * units (str) - the units of the dimension. Must be one of mm, cm, inch, or pts
            
        Returns:
        
            * length in inches
            
        Example:
        
        >>> converted = Set._inches(10, 'cm') # Convert 10cm to inches
        >>> print '%.3f' %(converted) # Check the result
        3.937
        """
    unitconverter = {'pts': 1.0 / 72.0, 'mm': 0.039370079, 'cm': 0.39370079,
        'inch': 1.0}
    inches = length * unitconverter[units]
    return inches
