@Override
  public String toString() {
    return "[FunctionContextImpl:"
        + "functionId="
        + functionId
        + ";args="
        + args
        + ";principal="
        + getPrincipal()
        + ']';
  }
Get the identifier of the running function used for logging and administration purposes

@return String uniquely identifying this running instance
@see Function#getId()
geode-core/src/main/java/org/apache/geode/internal/cache/execute/FunctionContextImpl.java