Cargo Features

evcxr_runtime has no features set by default.

[dependencies]
evcxr_runtime = { version = "1.1.0", features = ["bytes"] }
bytes = base64

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

base64 bytes?

Enables base64 ^0.13.0