https://github.com/jump-dev/MathOptInterface.jl/blob/master/src/Bridges/Constraint/function_conversion.jl
Actual bridge: https://github.com/jump-dev/MathOptInterface.jl/blob/7923c601506cba2edb44f25eca830fc74d7cfe70/src/Bridges/Constraint/function_conversion.jl