Require namespace
Examples
isTRUE(require_namespace("base")) # returns invisibly
#> [1] TRUE
try(require_namespace("1package")) # (using a purposefully bad name)
#> Error : <namespaceError> No package found called '1package'
#> package:fuj
require_namespace("base", "utils")
try(require_namespace("base>=3.5", "utils>4.0", "fuj==10.0"))
#> Error : <namespaceVersionError> Package version requirement not meet:
#> fuj: 0.2.1.9003 == 10.0
#> package:fuj