std::vector< value_type > data;
std::vector< size_t> indices;
data.reserve( nSetSize );
indices.reserve( nSetSize );
for ( size_t key = 0; key < nSetSize; ++key ) {
std::vector< value_type > data;
std::vector< size_t> indices;
data.reserve( nSetSize );
indices.reserve( nSetSize );
for ( size_t key = 0; key < nSetSize; ++key ) {