public static String toString(Object obj) {
        return obj == null ? "" : obj.toString();
    }
<p>Gets the {@code toString} of an {@code Object} returning
an empty string ("") if {@code null} input.</p>

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

@see StringUtils#defaultString(String)
@see String#valueOf(Object)
@param obj  the Object to {@code toString}, 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