buildMonomial(degree /*int*/, coefficient /*int*/) {
			if (degree < 0) {
				throw new IllegalArgumentException();
			}
			if (coefficient === 0) {
				return this.zero;
			}
			const coefficients = new Int32Array(degree + 1);
			coefficients[0] = coefficient;
			return new GenericGFPoly(this, coefficients);
		}
@return the monomial representing coefficient * x^degree