     
     /// Create CGGlyph from a character.
     ///
-    /// - Parameter character: A character to extract glyph.
+    /// - Parameter character: The character to extract glyph.
     /// - Returns: A CGGlyph for passed-in character based on the receiver font.
     func glyph(for character: Character) -> CGGlyph {
         


extension NSFont {
    
    /// width of SPACE character
    var spaceWidth: CGFloat {
        
        return self.advancement(character: " ").width
    }
    
    
    /// Calculate advancement of a character using CoreText.
    ///
    /// - Parameter character: Character to calculate advancement.
    /// - Returns: Advancement of passed-in character.
    private func advancement(character: Character) -> NSSize {
        
        let glyph = (self as CTFont).glyph(for: character)
        
        return self.advancement(forCGGlyph: glyph)
    }
    
}

    /// Get advancement of a glyph.
    ///
    /// - Parameters:
    ///   - glyph: The glyph to calculate advancement.
    ///   - orientation: Drawing orientation.
    /// - Returns: Advancement of passed-in glyph.
    func advance(for glyph: CGGlyph, orientation: CTFontOrientation = .horizontal) -> CGSize {
