public void setNamespaceContext(Map<String, String> prefix2uri) {
        this.prefix2uri = prefix2uri == null
            ? Collections.<String, String> emptyMap()
            : Collections.unmodifiableMap(prefix2uri);
    }
public void setNamespaceContext ( Map < String , String > prefix2uri ) { this . prefix2uri = prefix2uri == null ? Collections . < String , String > emptyMap ( ) : Collections . unmodifiableMap ( prefix2uri ) ; }
Establish a namespace context that will be used in for the
XPath.

<p>Without a namespace context (or with an empty context) the
XPath expressions will only use local names for elements and
attributes.</p>

@param prefix2uri maps from prefix to namespace URI.