//! Returns Feature object by the given Model index.
//! Returns 0 if the given index is not index of a feature
//! Returns Feature object by the given Model index.
//! Returns 0 if the given index is not index of a feature
//! Returns QModelIndex which corresponds to the given feature
//! If the feature is not found then index is not valid
//! Returns QModelIndex which corresponds to the given feature
//! If the feature is not found then index is not valid
//! Returns index corresponded to the group
virtual QModelIndex findGroup(const std::string& theGroup) const = 0;
//! Returns index corresponded to the group
virtual QModelIndex findGroup(const std::string& theGroup) const = 0;