code: public static FileFilter xor(FileFilter leftOperand, FileFilter rightOperand) {
      return compose(LogicalOperator.XOR, leftOperand, rightOperand);
    }
docs: Composes two {@link FileFilter} operands in an expression joined by the logical XOR operator.
  
  @param leftOperand {@link FileFilter} operand used in the left hand side of the logical expression.
  @param rightOperand {@link FileFilter} operand used in the right hand side of the logical expression.
  @return a {@link FileFilter} implementation composed of two {@link FileFilter} operands in an expression
  joined by the logical XOR operator.
  @see #compose(org.cp.elements.lang.LogicalOperator, java.io.FileFilter, java.io.FileFilter)
  @see org.cp.elements.lang.LogicalOperator#XOR
  @see java.io.FileFilter