EntityMerger::checkIfEmptyValue

protected function checkIfEmptyValue($type, $value)
{
	if($type === 'string' ||
		$type === 'char' ||
		$type === 'datetime' ||
		$type === 'date' ||
		$type === 'crm_status' ||
		$type === 'crm_currency'
	)
	{
		return $value == '';
	}
	elseif($type === 'double')
	{
		return $value == 0.0;
	}
	elseif($type === 'integer' ||
		$type === 'user' ||
		$type === 'crm_company' ||
		$type === 'crm_contact'
	)
	{
		return $value == 0;
	}
	elseif($type === 'user_field')
	{
		if(is_array($value))
		{
			return empty($value);
		}
		elseif(is_string($value))
		{
			return $value == '';
		}
		return $value == null;
	}
	return $value == null;
}