Maintainer: ‘Xin Guo <x.guo@polyu.edu.hk>’

No Authors@R field in DESCRIPTION.
Please add one, modifying
  Authors@R: c(person(given = "Xin",
                      family = "Guo",
                      role = c("aut", "cre"),
                      email = "x.guo@polyu.edu.hk"),
               person(given = "Qiang",
                      family = "Fu",
                      role = "aut",
                      email = "qiang.fu@ubc.ca"))
as necessary.
Maintainer: ‘Xin Guo <x.guo@polyu.edu.hk>’

No Authors@R field in DESCRIPTION.
Please add one, modifying
  Authors@R: c(person(given = "Xin",
                      family = "Guo",
                      role = c("aut", "cre"),
                      email = "x.guo@polyu.edu.hk"),
               person(given = "Qiang",
                      family = "Fu",
                      role = "aut",
                      email = "qiang.fu@ubc.ca"))
as necessary.