Checks for attribute nodes.
The following construct(s) refer to this construct:
An AttributeTest
checks for an attribute node and its name
and can be of one of these forms:
attribute()
and attribute(*)
match any single
attribute node, regardless of its name or type.
attribute(QName)
matches any
attribute node whose name is QName
, regardless of its type.
The attribute test attribute(id)
matches any attribute
node whose name is "id".