Add GraphProperties and property caching

src/node/create.jl

@@ -1,3 +1,43 @@
+
+DataTaskNode(t::AbstractDataTask) = DataTaskNode(
+    t,
+    Vector{Node}(),
+    Vector{Node}(),
+    UUIDs.uuid1(rng[threadid()]),
+    missing,
+    missing,
+    missing,
+)
+ComputeTaskNode(t::AbstractComputeTask) = ComputeTaskNode(
+    t,
+    Vector{Node}(),
+    Vector{Node}(),
+    UUIDs.uuid1(rng[threadid()]),
+    missing,
+    missing,
+    Vector{NodeFusion}(),
+)
+
+copy(m::Missing) = missing
+copy(n::ComputeTaskNode) = ComputeTaskNode(
+    copy(n.task),
+    copy(n.parents),
+    copy(n.children),
+    UUIDs.uuid1(rng[threadid()]),
+    copy(n.nodeReduction),
+    copy(n.nodeSplit),
+    copy(n.nodeFusions),
+)
+copy(n::DataTaskNode) = DataTaskNode(
+    copy(n.task),
+    copy(n.parents),
+    copy(n.children),
+    UUIDs.uuid1(rng[threadid()]),
+    copy(n.nodeReduction),
+    copy(n.nodeSplit),
+    copy(n.nodeFusion),
+)
+
 """
     make_node(t::AbstractTask)