You're seeing just the function find, go back to ExKcal.Products module for more information.
Link to this function

find(regex, products, fields \\ [:name, :description])


find(Regex.t(), t(), list()) :: {:ok, list()} | {:not_found, nil}

Find Products by any field.


Match is done against space-separated, merged list of requested fields. This means that there is only one end of line, not multiple like in case of multiple, separate fields.