### Question:
ExpressionPropertyConverter { public static Expression wbFromDMN(final org.kie.dmn.model.api.Expression dmn, final BiConsumer<String, HasComponentWidths> hasComponentWidthsConsumer) { if (dmn instanceof org.kie.dmn.model.api.LiteralExpression) { final LiteralExpression e = LiteralExpressionPropertyConverter.wbFromDMN((org.kie.dmn.model.api.LiteralExpression) dmn); hasComponentWidthsConsumer.accept(dmn.getId(), e); return e; } else if (dmn instanceof org.kie.dmn.model.api.Context) { final Context e = ContextPropertyConverter.wbFromDMN((org.kie.dmn.model.api.Context) dmn, hasComponentWidthsConsumer); hasComponentWidthsConsumer.accept(dmn.getId(), e); return e; } else if (dmn instanceof org.kie.dmn.model.api.Relation) { final Relation e = RelationPropertyConverter.wbFromDMN((org.kie.dmn.model.api.Relation) dmn, hasComponentWidthsConsumer); hasComponentWidthsConsumer.accept(dmn.getId(), e); return e; } else if (dmn instanceof org.kie.dmn.model.api.List) { final List e = ListPropertyConverter.wbFromDMN((org.kie.dmn.model.api.List) dmn, hasComponentWidthsConsumer); hasComponentWidthsConsumer.accept(dmn.getId(), e); return e; } else if (dmn instanceof org.kie.dmn.model.api.Invocation) { final Invocation e = InvocationPropertyConverter.wbFromDMN((org.kie.dmn.model.api.Invocation) dmn, hasComponentWidthsConsumer); hasComponentWidthsConsumer.accept(dmn.getId(), e); return e; } else if (dmn instanceof org.kie.dmn.model.api.FunctionDefinition) { final FunctionDefinition e = FunctionDefinitionPropertyConverter.wbFromDMN((org.kie.dmn.model.api.FunctionDefinition) dmn, hasComponentWidthsConsumer); hasComponentWidthsConsumer.accept(dmn.getId(), e); return e; } else if (dmn instanceof org.kie.dmn.model.api.DecisionTable) { final DecisionTable e = DecisionTablePropertyConverter.wbFromDMN((org.kie.dmn.model.api.DecisionTable) dmn); hasComponentWidthsConsumer.accept(dmn.getId(), e); return e; } return null; }  static Expression wbFromDMN(final org.kie.dmn.model.api.Expression dmn,
                                       final BiConsumer<String, HasComponentWidths> hasComponentWidthsConsumer); static org.kie.dmn.model.api.Expression dmnFromWB(final Expression wb,
                                                             final Consumer<ComponentWidths> componentWidthsConsumer);  }### Answer:
@Test public void testWBFromDMN_NullConversion() { assertThat(ExpressionPropertyConverter.wbFromDMN(null, hasComponentWidthsConsumer)).isNull(); }