use dict string key

src/interface.jl

@@ -64,10 +64,10 @@ function runMCTS(
   saveSimulatedNode::Bool=false,
   multithread=false,
   )::NamedTuple{(:root, :bestNextState, :bestTerminalState, :highValueStateList),
-                Tuple{MCTSNode,T,T,Vector{Dict{Symbol,Any}}}} where {T<:Any}
+                Tuple{MCTSNode,T,T,Vector{Dict{String,Any}}}} where {T<:Any}
 
   root = MCTSNode("root", initialstate, 0, 0, 0, 0, false, nothing, Dict{String,MCTSNode}(),
-                  Dict{Symbol,Any}())
+                  Dict{String,Any}())
 
   # storage for holding all high reward terminal nodes
   highValueState = Channel{Any}(100)
@@ -125,7 +125,7 @@ function runMCTS(
   bestTerminalState = selectBestTrajectoryNode(root)
 
   # take all high value state from highValueState channel and put it in a list
-  highValueStateList = Vector{Dict{Symbol, Any}}()
+  highValueStateList = Vector{Dict{String, Any}}()
   while !isempty(highValueState)
     push!(highValueStateList, take!(highValueState))
   end