constant                Identify Constant Features of an Object
constant.data.frame     Identify Constant Features of a Data Frame
constant.grouped_df     Identify Constant Features of a Grouped Data
                        Frame
detect                  Sort column subsets.
dup                     Show duplicate or duplicated elements.
dup.grouped_df          Show records with duplicate or duplicated
                        values of grouping variables.
dupGroups               Calculate dupGroups.
dupGroups.grouped_df    Count records with with duplicate or duplicated
                        values of grouping variables.
enumerate               Count unique combinations of items in specified
                        columns.
ignore                  Drop columns in x that are present in y.
informative             Drop columns in x that are entirely NA.
informative.data.frame
                        Drop columns in x that are entirely NA.
itemize                 Show unique combinations of items in specified
                        columns
key                     Fetch the key.
key.grouped_df          Fetch the key for a grouped_df as character
                        vector
na                      Show na elements.
na.grouped_df           Show records with NA values of grouping
                        variables.
naGroups                Calculate naGroups.
naGroups.grouped_df     Count records with NA values of grouping
                        variables.
safe_join               Join Data Safely
safe_join.data.frame    Join Data Frames Safely
sort.grouped_df         Arrange by groups.
static                  Find unique records for subset of columns with
                        one unique value.
status                  Report status.
status.grouped_df       Report status with respect to grouping
                        variables.
unsorted                Show unsorted elements.
unsorted.grouped_df     Find records whose relative positons would
                        change if sorted.
weak                    Show na, duplicate, or duplicated elements.
weak.grouped_df         Show records with NA, duplicate or duplicated
                        values of grouping variables.
