Test whether the string represents a group header. Note: "[]" is not considered to be a valid group header.
assert( isGroupHeader("[Group]")); assert( isGroupHeader("[Group] ")); assert(!isGroupHeader("[]")); assert(!isGroupHeader("[Group")); assert(!isGroupHeader("Group]"));
See Implementation
Test whether the string represents a group header. Note: "[]" is not considered to be a valid group header.