question: protected AttributesImpl startPrefixMapping ( Element element , NamespaceStack namespaceStack ) throws SAXException { AttributesImpl namespaceAttributes = null ; Namespace elementNamespace = element . getNamespace ( ) ; if ( ( elementNamespace != null ) && ! isIgnoreableNamespace ( elementNamespace , namespaceStack ) ) { namespaceStack . push ( elementNamespace ) ; contentHandler . startPrefixMapping ( elementNamespace . getPrefix ( ) , elementNamespace . getURI ( ) ) ; namespaceAttributes = addNamespaceAttribute ( namespaceAttributes , elementNamespace ) ; } List < Namespace > declaredNamespaces = element . declaredNamespaces ( ) ; for ( Namespace namespace : declaredNamespaces ) { if ( ! isIgnoreableNamespace ( namespace , namespaceStack ) ) { namespaceStack . push ( namespace ) ; contentHandler . startPrefixMapping ( namespace . getPrefix ( ) , namespace . getURI ( ) ) ; namespaceAttributes = addNamespaceAttribute ( namespaceAttributes , namespace ) ; } } return namespaceAttributes ; }
target:  Fires a SAX startPrefixMapping event for all the namespaceStack which have just come into scope