Validates that a data.frame contains all specified columns. Equivalent to
require_names(cols, mode = "superset") with column wording in the
message.
See also
Other structure checks:
require_dim(),
require_length(),
require_length_matches(),
require_length_max(),
require_length_min(),
require_named(),
require_names(),
require_ncol_matches(),
require_ncol_min(),
require_nrow_matches(),
require_nrow_min(),
require_scalar(),
require_sorted(),
require_unique_names()