protected void setArraySeparator(String arraySeparator) {
        if (arraySeparator == null) {
            arraySeparator = "";
        }
        this.arraySeparator = arraySeparator;
    }
<p>Sets the array separator text.</p>

<p><code>null</code> is accepted, but will be converted to
an empty String.</p>

@param arraySeparator  the new array separator text
android/android_framework/base/src/main/java/lang3/builder/ToStringStyle.java