### Question:
TSTargetDeclType implements TSTargetType { @Override public ConversionCoverage conversionCoverage() { return this.mappingExpression.conversionCoverage(); } TSTargetDeclType(TypeMappingExpression mappingExpression, Map<String, TSTargetType> typeParametersTypes, Supplier<String> javaType, Supplier<String> namespace);   TSTargetDeclType(TypeMappingExpression mappingExpression, Map<String, TSTargetType> typeParametersTypes, boolean ignoreSelfNamespace); String getJavaType(); @Override ConversionCoverage conversionCoverage(); @Override String toString(); @Override boolean isReferenceType(); @Override List<String> typeParameters(); @Override Map<String, TSTargetType> typeParameterTypes(); @Override TSTargetType mapNameSpace(NameSpaceMapper nsm); @Override TSTargetType withTypeParams(Map<String, TSTargetType> typeParams);  }### Answer:
@Test @DisplayName("check mapping expression to be SUBTYPE for regular mapping in TSTargetDeclType") void conversionCoverage() { TypeMappingExpression expr = CustomMappingParserFactory.parser().parse("String->sting").orElse(null); TSTargetDeclType testee = new TSTargetDeclType(expr,new HashMap<>(),false); assertEquals(testee.conversionCoverage(),SUBTYPES); }