- isSquare(value): value is
| "h1"
| "h2"
| "h3"
| "h4"
| "h5"
| "h6"
| "d1"
| "d2"
| "d3"
| "d4"
| "d5"
| "d6"
| "d7"
| "d8"
| "a1"
| "a2"
| "a3"
| "a4"
| "a5"
| "a6"
| "a7"
| "a8"
| "b1"
| "b2"
| "b3"
| "b4"
| "b5"
| "b6"
| "b7"
| "b8"
| "g1"
| "g2"
| "g3"
| "g4"
| "g5"
| "g6"
| "g7"
| "g8"
| "c1"
| "c2"
| "c3"
| "c4"
| "c5"
| "c6"
| "c7"
| "c8"
| "e1"
| "e2"
| "e3"
| "e4"
| "e5"
| "e6"
| "e7"
| "e8"
| "f1"
| "f2"
| "f3"
| "f4"
| "f5"
| "f6"
| "f7"
| "f8"
| "h7"
| "h8" Returns value is
| "h1"
| "h2"
| "h3"
| "h4"
| "h5"
| "h6"
| "d1"
| "d2"
| "d3"
| "d4"
| "d5"
| "d6"
| "d7"
| "d8"
| "a1"
| "a2"
| "a3"
| "a4"
| "a5"
| "a6"
| "a7"
| "a8"
| "b1"
| "b2"
| "b3"
| "b4"
| "b5"
| "b6"
| "b7"
| "b8"
| "g1"
| "g2"
| "g3"
| "g4"
| "g5"
| "g6"
| "g7"
| "g8"
| "c1"
| "c2"
| "c3"
| "c4"
| "c5"
| "c6"
| "c7"
| "c8"
| "e1"
| "e2"
| "e3"
| "e4"
| "e5"
| "e6"
| "e7"
| "e8"
| "f1"
| "f2"
| "f3"
| "f4"
| "f5"
| "f6"
| "f7"
| "f8"
| "h7"
| "h8"
Whether the given value represents a valid Square or not.