package de.gurkenlabs.litiengine.entities;

public enum PropState {
  INTACT,
  DAMAGED,
  DESTROYED;

  public String spriteString() {
    return this.name().toLowerCase();
  }
}

@@ -110,75 +110,164 @@
 %0A  p
-ublic String spriteString() %7B%0D%0A    return this.name().toLowerCase()
+rivate final String str;%0D%0A%0D%0A  private PropState() %7B%0D%0A    this.str = this.name().toLowerCase();%0D%0A  %7D%0D%0A%0D%0A  public String spriteString() %7B%0D%0A    return this.str
 ;%0D%0A 

Store lower-case string because conversion takes time.