Attribute = object
  name*: string
  count*: int16
  dtype*: DataType
  offset*: int16
  location*: int16

AttributeList = seq[Attribute]

DataType = enum
  Unknown, Byte = 5120, UByte = 5121, Short = 5122, UShort = 5123, Int = 5124,
  UInt = 5125, Float = 5126, HalfFloat = 5131

proc `[]`(layout: AttributeList; name: string): Attribute {.
    ...raises: [KeyError, ValueError], tags: [].}

proc add(layout: var AttributeList; attr: Attribute) {....raises: [], tags: [].}

proc contains(layout: AttributeList; name: string): bool {....raises: [], tags: [].}

func size(dtype: DataType): int16 {....raises: [], tags: [].}

func stride(layout: AttributeList; align: int32 = 4): int32 {....raises: [],
    tags: [].}