@staticmethod
def prepare_required_raw_item(item):
    """Prepare required field item.

        Convert replaces any special "dimensions#", "meta#" or "value_meta" occurrences into
        spark rdd syntax to fetch field value.

        """
    if item.startswith('dimensions#'):
        field_name = item.replace('dimensions#', '')
        return "metric.dimensions['%s']" % field_name
    elif item.startswith('meta#'):
        field_name = item.replace('meta#', '')
        return "meta['%s']" % field_name
    elif item.startswith('value_meta#'):
        field_name = item.replace('value_meta#', '')
        return "metric.value_meta['%s']" % field_name
    else:
        return item
