code: public void setValue(String expression, Object value) {
          ValueExpression exp = factory.createValueExpression(
                                    elManager.getELContext(),
                                    bracket(expression), Object.class);
          exp.setValue(elManager.getELContext(), value);
      }
docs: Sets an expression with a new value.
  The target expression is evaluated, up to the last property resolution,
  and the resultant (base, property) pair is set to the provided value.
  
  @param expression The target expression
  @param value The new value to set.
  @throws PropertyNotFoundException if one of the property
  resolutions failed because a specified variable or property
  does not exist or is not readable.
  @throws PropertyNotWritableException if the final variable or
  property resolution failed because the specified
  variable or property is not writable.
  @throws ELException if an exception was thrown while attempting to
  set the property or variable. The thrown exception
  must be included as the cause property of this exception, if
  available.