code: public boolean getBoolean(String propertyPath) throws PropertyException {
  		Object o = getValue(propertyPath);
  		return Boolean.parseBoolean(o.toString());
  	}
docs: Get the boolean-value from the property path.
  
  @param propertyPath
  Example: foo.bar.key
  @return the {@link Boolean} value for the given propertyPath
  @throws PropertyException
  If the propertyKey-Path is not a property key or is a not
  part of a property path; also when the value is not a
  {@link Boolean}