ERROR: LoadError: ArgumentError: collection must be non-empty
Stacktrace:
 [1] _findmax(::Array{Any,1}, ::Colon) at ./array.jl:2056
 [2] #findmax#565 at ./reducedim.jl:810 [inlined]
 [3] #findmax at ./none:0 [inlined]
 [4] #argmax#567 at ./reducedim.jl:875 [inlined]
 [5] argmax(::Array{Any,1}) at ./reducedim.jl:875
 [6] group_docs(::Array{Any,1}) at ./clustering.jl:123
 [7] print_threads(::String) at ./tgnews.jl:91
 [8] main(::Bool) at ./tgnews.jl:189
 [9] main() at ./tgnews.jl:180
 [10] top-level scope at none:0
 [11] include at ./boot.jl:317 [inlined]
 [12] include_relative(::Module, ::String) at ./loading.jl:1044
 [13] include(::Module, ::String) at ./sysimg.jl:29
 [14] exec_options(::Base.JLOptions) at ./client.jl:266
 [15] _start() at ./client.jl:425
in expression starting at ./tgnews.jl:193