public static String toString(Object obj, String nullStr) {
        return obj == null ? nullStr : obj.toString();
    }
<p>Gets the {@code toString} of an {@code Object} returning
a specified text if {@code null} input.</p>

<pre>
ObjectUtils.toString(null, null)           = null
ObjectUtils.toString(null, "null")         = "null"
ObjectUtils.toString("", "null")           = ""
ObjectUtils.toString("bat", "null")        = "bat"
ObjectUtils.toString(Boolean.TRUE, "null") = "true"
</pre>

@see StringUtils#defaultString(String,String)
@see String#valueOf(Object)
@param obj  the Object to {@code toString}, may be null
@param nullStr  the String to return if {@code null} input, may be null
@return the passed in Object's toString, or nullStr if {@code null} input
@since 2.0
android/android_framework/base/src/main/java/lang3/ObjectUtils.java