anyOf [string, Array<string>]
The output fields at which to write the start and end bin values. This can be either a string or an array of strings with two elements denoting the name for the fields for bin start and bin end respectively. If a single string (e.g., "val") is provided, the end field will be "val_end".
anyOf [boolean, BinParams]
An object indicating bin properties, or simply true for using default bin parameters.
string