Gets a 64-bit floating point number at the specified absolute
{@code index} in this buffer. This method does not modify
{@code readerIndex} or {@code writerIndex} of this buffer.
@throws IndexOutOfBoundsException
if the specified {@code index} is less than {@code 0} or
{@code index + 8} is greater than {@code this.capacity}
Gets a 64-bit floating point number at the specified absolute {@code index} in this buffer. This method does not modify {@code readerIndex} or {@code writerIndex} of this buffer.
@throws IndexOutOfBoundsException if the specified {@code index} is less than {@code 0} or {@code index + 8} is greater than {@code this.capacity}