code: public Boolean interpret(Object securityExpression) {
          Boolean interpretation = Boolean.FALSE;
  
          if (securityExpression instanceof Boolean) {
              interpretation = Boolean.class.cast(securityExpression);
          } else if (securityExpression instanceof String) {
              interpretation = expression((String) securityExpression);
          }
  
          return interpretation;
      }
docs: This methods will interpret any security expression. It will handle it
  accordingly in function of its type.
  <p>
  For now, Boolean will be interpreted as Boolean and String will be
  interpreted by the {@link ELService} as an Expression Language from the JSR 341.
  
  @param securityExpression the security expression.
  @return True if the security expression interpretation is secured.