static get UNIONS() {
    return {
      a: ['p', 'p'],
      c: ['p', 'r'],
      d: ['p', 'n'],
      e: ['p', 'b'],
      f: ['p', 'q'],
      g: ['p', 'k'],
      h: ['r', 'r'],
      i: ['r', 'n'],
      j: ['r', 'b'],
      l: ['r', 'q'],
      m: ['r', 'k'],
      o: ['n', 'n'],
      s: ['n', 'b'],
      t: ['n', 'q'],
      u: ['n', 'k'],
      v: ['b', 'b'],
      w: ['b', 'q'],
      x: ['b', 'k'],
      y: ['q', 'q'],
      z: ['q', 'k'],
      '@': ['k', 'k']
    };
  }
// Unions (left = white if upperCase, black otherwise)
Unions (left = white if upperCase, black otherwise)
Unions ( left = white if upperCase black otherwise )
static get UNIONS() {
    return {
      a: ['p', 'p'],
      c: ['p', 'r'],
      d: ['p', 'n'],
      e: ['p', 'b'],
      f: ['p', 'q'],
      g: ['p', 'k'],
      h: ['r', 'r'],
      i: ['r', 'n'],
      j: ['r', 'b'],
      l: ['r', 'q'],
      m: ['r', 'k'],
      o: ['n', 'n'],
      s: ['n', 'b'],
      t: ['n', 'q'],
      u: ['n', 'k'],
      v: ['b', 'b'],
      w: ['b', 'q'],
      x: ['b', 'k'],
      y: ['q', 'q'],
      z: ['q', 'k'],
      '@': ['k', 'k']
    };
  }
static get UNIONS ( ) { return { a : [ 'p' , 'p' ] , c : [ 'p' , 'r' ] , d : [ 'p' , 'n' ] , e : [ 'p' , 'b' ] , f : [ 'p' , 'q' ] , g : [ 'p' , 'k' ] , h : [ 'r' , 'r' ] , i : [ 'r' , 'n' ] , j : [ 'r' , 'b' ] , l : [ 'r' , 'q' ] , m : [ 'r' , 'k' ] , o : [ 'n' , 'n' ] , s : [ 'n' , 'b' ] , t : [ 'n' , 'q' ] , u : [ 'n' , 'k' ] , v : [ 'b' , 'b' ] , w : [ 'b' , 'q' ] , x : [ 'b' , 'k' ] , y : [ 'q' , 'q' ] , z : [ 'q' , 'k' ] , '@' : [ 'k' , 'k' ] } ; }
Unions (left = white if upperCase, black otherwise)
Unions ( left = white if upperCase black otherwise )