public static String stripToEmpty(String str) {
        return str == null ? EMPTY : strip(str, null);
    }
<p>Strips whitespace from the start and end of a String  returning
an empty String if {@code null} input.</p>

<p>This is similar to {@link #trimToEmpty(String)} but removes whitespace.
Whitespace is defined by {@link Character#isWhitespace(char)}.</p>

<pre>
StringUtils.stripToEmpty(null)     = ""
StringUtils.stripToEmpty("")       = ""
StringUtils.stripToEmpty("   ")    = ""
StringUtils.stripToEmpty("abc")    = "abc"
StringUtils.stripToEmpty("  abc")  = "abc"
StringUtils.stripToEmpty("abc  ")  = "abc"
StringUtils.stripToEmpty(" abc ")  = "abc"
StringUtils.stripToEmpty(" ab c ") = "ab c"
</pre>

@param str  the String to be stripped, may be null
@return the trimmed String, or an empty String if {@code null} input
@since 2.0
android/android_framework/base/src/main/java/lang3/StringUtils.java