@uml
Get the last node associated with a specific {@code label}.
<p>For example, for pattern {@code <id:ID>}, {@code get("id")} returns the
node matched for that {@code ID}. If more than one node
matched the specified label, only the last is returned. If there is
no node associated with the label, this returns {@code null}.</p>
<p>Pattern tags like {@code <ID>} and {@code <expr>} without labels are
considered to be labeled with {@code ID} and {@code expr}, respectively.</p>
@param label The label to check.
@return The last {@link ParseTree} to match a tag with the specified
label, or {@code null} if no parse tree matched a tag with the label.
@uml Get the last node associated with a specific {@code label}.
<p>For example, for pattern {@code <id:ID>}, {@code get("id")} returns the node matched for that {@code ID}. If more than one node matched the specified label, only the last is returned. If there is no node associated with the label, this returns {@code null}.</p>
<p>Pattern tags like {@code <ID>} and {@code <expr>} without labels are considered to be labeled with {@code ID} and {@code expr}, respectively.</p>
@param label The label to check.
@return The last {@link ParseTree} to match a tag with the specified label, or {@code null} if no parse tree matched a tag with the label.