can't find class (perhaps a bug) about etree HOT 2 CLOSED

.               Selects the current element
..              Selects the parent of the current element
*               Selects all child elements
//              Selects all descendants of the current element
tag             Selects all child elements with the given tag
[#]             Selects the element of the given index (1-based,
                  negative starts from the end)
[@attrib]       Selects all elements with the given attribute
[@attrib='val'] Selects all elements with the given attribute set to val
[tag]           Selects all elements with a child element named tag
[tag='val']     Selects all elements with a child element named tag
                  and text matching val
[text()]        Selects all elements with non-empty text
[text()='val']  Selects all elements whose text matches val