@type t() :: %PolarExpress.Schemas.MeterUpdate{
  aggregation: term(),
  custom_label: term(),
  custom_multiplier: term(),
  filter: term(),
  is_archived: term(),
  metadata: term(),
  name: term(),
  unit: term()
}

• aggregation - The aggregation to apply on the filtered events to calculate the meter. Nullable.
• custom_label - The label for the custom unit. Required when unit is 'custom'. Nullable.
• custom_multiplier - The multiplier to convert from base unit to display scale. Required when unit is 'custom'. Nullable.
• filter - The filter to apply on events that'll be used to calculate the meter. Nullable.
• is_archived - Whether the meter is archived. Archived meters are no longer used for billing. Nullable.
• metadata - Key-value object allowing you to store additional information.

The key must be a string with a maximum length of 40 characters. The value must be either:

• A string with a maximum length of 500 characters
• An integer
• A floating-point number
• A boolean

You can store up to 50 key-value pairs.

• name - The name of the meter. Will be shown on customer's invoices and usage. Nullable.
• unit - The unit of the meter. Nullable.