Function esl01_dag::namedag::build

pub fn build<F>(
    map: &mut SyncableIdMap, 
    dag: &mut SyncableIdDag<IndexedLogStore>, 
    parent_names_func: F, 
    master_heads: &[VertexName], 
    non_master_heads: &[VertexName]
) -> Result<()> where
    F: Fn(VertexName) -> Result<Vec<VertexName>>, 

Build IdMap and Segments for the given heads.