Changes

| Constructs and returns a new map. The zero-argument form of the function returns an empty ''map'' whose collation is the default collation in the static context. It is equivalent to calling the one-argument form of the function with an empty sequence as the value of the first argument.

The one-argument form of the function returns a ''map'' that is formed by combining the contents of the maps supplied in the <code>$maps</code> argument. It is equivalent to calling the two-argument form of the function with the default collation from the static context as the second argument.

# There is one entry in the new map for each distinct key value present in the union of the input maps, where keys are considered distinct according to the rules of the <code>distinct-values</code> function with <code>$collation</code> as the collation.