public BitChromosome shiftLeft(final int n) {
		final var genes = _genes.copy();
		if (n >= 0) {
			genes.shiftLeft(n);
		} else {
			genes.shiftRight(Math.abs(n));
		}
		return new BitChromosome(genes, _p);
	}
Returns a new {@code BitChromosome} whose value is ({@code this << n}).
The shift distance, n, may be negative, in which case this method performs
a right shift.

@param n shift distance, in bits
@return {@code this << n}
jenetics/src/main/java/io/jenetics/BitChromosome.java