remove logger

src/base/logging/log.jl

@@ -56,4 +56,3 @@ end
 @_make_logging_tag models "model-related messages"
 @_make_logging_tag io "messages and warnings from model input/output"
 @_make_logging_tag perf "performance-related tracing information"
-log_models(true)

src/base/utils/Reaction.jl

@@ -61,10 +61,7 @@ function is_mass_balanced(model::StandardModel, rxn::Reaction)
     atom_balances = Dict{String,Float64}() # float here because stoichiometry is not Int
     for (met, stoich) in rxn.metabolites
         atoms = metabolite_formula(model, met)
-        if isnothing(atoms) # ignore blanks 
-            @_models_log @warn "$met has no atoms associated with it."
-            continue
-        end
+        isnothing(atoms) && throw(ErrorException("Metabolite $met does not have a formula assigned to it."))
         for (k, v) in atoms
             atom_balances[k] = get(atom_balances, k, 0) + v * stoich
         end