The absolute base identifier
The reference to relativize
A relative reference from base to reference, or the normalized absolute reference if not relativizable
RangeError If base is not a valid absolute identifier or reference is not a valid
relative reference, for instance because it carries an isolated UTF-16 surrogate
RangeError If the resolved path contains tree-climbing segments that would go above the root
Creates a relative reference from base to reference.
base, yieldsreference