public byte getByte(final int index) {
        this.checkIndexLength(index, SIZE_OF_BYTE);
        return this.getByteUnchecked(index);
    }
Gets a byte at the specified absolute {@code index} in this buffer.

@throws IndexOutOfBoundsException if the specified {@code index} is less than {@code 0} or
{@code index + 1} is greater than {@code this.length()}
embulk-core/src/main/java/org/embulk/exec/Slice.java