jdk.compiler/share/classes/com/sun/tools/javac/util/GraphUtils.java
254│ return p.toString().replaceAll(",", " ")
255│ .replaceAll("\\{", "[")
256│ .replaceAll("\\}", "]");

This could be

    return p.toString().replace(',', ' ')
        .replace('{', '[')
        .replace('}', ']');