### Question:
TypeScriptUtils { static String sanitizePropertyName(String memberName) { return isValidPropertyName(memberName) ? memberName : StringUtils.escapeJavaString(memberName, ""); } private  TypeScriptUtils();   }### Answer:
@Test public void sanitizesPropertyNames() { assertThat(TypeScriptUtils.sanitizePropertyName("foo"), equalTo("foo")); assertThat(TypeScriptUtils.sanitizePropertyName("$foo"), equalTo("$foo")); assertThat(TypeScriptUtils.sanitizePropertyName("_Foo"), equalTo("_Foo")); assertThat(TypeScriptUtils.sanitizePropertyName("_Foo.bar"), equalTo("\"_Foo.bar\"")); assertThat(TypeScriptUtils.sanitizePropertyName("!foo"), equalTo("\"!foo\"")); assertThat(TypeScriptUtils.sanitizePropertyName("foo?"), equalTo("\"foo?\"")); }