btree_delete_i8_sp2d Subroutine

      SUBROUTINE btree_delete_i8_sp2d (tree, keys, values)
         TYPE(btree_i8_sp2d), INTENT(INOUT) :: tree
         INTEGER(KIND=keyt), DIMENSION(:), INTENT(OUT), OPTIONAL :: keys
         TYPE(btree_data_sp2d), DIMENSION(:), INTENT(OUT), OPTIONAL :: values
         INTEGER :: pos
         !
         IF (ASSOCIATED(tree%b%root)) THEN
            pos = 0
            IF (PRESENT(keys) .AND. PRESENT(values)) THEN
               pos = 1
               CALL btree_delete_node_i8_sp2d (tree%b%root, pos, keys, values)
            ELSE
               CALL btree_delete_node_i8_sp2d (tree%b%root)
            END IF
         END IF
         NULLIFY (tree%b%root)
      END SUBROUTINE btree_delete_i8_sp2d