# Insert additional explicit calls to get the current `JNIEnv`
	#
	# This forces declaration of callbacks to Nit. The callbacks will be available in Java
	# but will be used mainly by the FFI itself.
	#
	# The developer can also customize the JNIEnv used by the FFI by redefining `Sys::jni_env`.
	private fun insert_artificial_callbacks(toolcontext: ToolContext)
	do
		var fcc = foreign_callbacks

		var modelbuilder = toolcontext.modelbuilder
		var mmodule = mpropdef.mclassdef.mmodule

		# We use callbacks from the C FFI since they will be called from generated C
		var c_language_visitor = toolcontext.ffi_language_assignation_phase.as(FFILanguageAssignationPhase).c_language
		if not mmodule.ffi_callbacks.keys.has(c_language_visitor) then
			mmodule.ffi_callbacks[c_language_visitor] = new HashSet[NitniCallback]
		end

		# Pointer::sys
		var pointer_class = modelbuilder.try_get_mclass_by_name(self, mmodule, "Pointer")
		assert pointer_class != null
		var pointer_sys_meth = modelbuilder.try_get_mproperty_by_name2(self, mmodule, pointer_class.mclass_type, "sys")
		assert pointer_sys_meth != null and pointer_sys_meth isa MMethod

		var explicit_call = new MExplicitCall(pointer_class.mclass_type, pointer_sys_meth, mmodule)
		fcc.callbacks.add(explicit_call)
		mmodule.ffi_callbacks[c_language_visitor].add(explicit_call)

		# Sys::jni_env
		var sys_class = modelbuilder.try_get_mclass_by_name(self, mmodule, "Sys")
		assert sys_class != null
		var sys_jni_env_meth = modelbuilder.try_get_mproperty_by_name2(self, mmodule, sys_class.mclass_type, "jni_env")
		if sys_jni_env_meth == null or not sys_jni_env_meth isa MMethod then
			toolcontext.error(self.location, "Java FFI Error: you must import the `java` module when using the FFI with Java")
			return
		end

		explicit_call = new MExplicitCall(sys_class.mclass_type, sys_jni_env_meth, mmodule)
		fcc.callbacks.add(explicit_call)
		mmodule.ffi_callbacks[c_language_visitor].add(explicit_call)

		# Sys::load_jclass
		var sys_jni_load_jclass_meth = modelbuilder.try_get_mproperty_by_name2(self, mmodule, sys_class.mclass_type, "load_jclass")
		assert sys_jni_load_jclass_meth != null
		assert sys_jni_load_jclass_meth isa MMethod

		explicit_call = new MExplicitCall(sys_class.mclass_type, sys_jni_load_jclass_meth, mmodule)
		fcc.callbacks.add(explicit_call)
		mmodule.ffi_callbacks[c_language_visitor].add(explicit_call)
		explicit_call.fill_type_for(fcc, mmodule)
	end