Fixed bug in write_to_file

Author: dlcole3

src/distributed/optigraph.jl

@@ -949,7 +949,7 @@ end
 function JuMP.write_to_file(rgraph::RemoteOptiGraph, filename::String)
     darray = rgraph.graph
 
-    f = @spawnat graph.worker begin
+    f = @spawnat rgraph.worker begin
         lgraph = Plasmo.local_graph(darray)
         JuMP.write_to_file(lgraph, filename)
     end

src/optigraph.jl

@@ -1502,7 +1502,7 @@ function JuMP.unregister(graph::GT, key::Symbol) where {GT<:AbstractOptiGraph}
 end
 
 """
-    write_to_file(graph::OptiGraph, filename::string)
+    write_to_file(graph::AbstractOptiGraph, filename::string)
 
 Write the model stored in `graph` to `filename.` See [`MOI.FileFormats.FileFormat`](@ref) 
 for a list of supported formats. Format is determined automatically based on given file