Document the presence of u64 for NumericError

Author: RazorBest

types/src/lib.rs

@@ -68,11 +68,11 @@ pub fn to_u64(value: i64, field: &str) -> Result<u64, NumericError> {
     u64::try_from(value).map_err(|_| NumericError::Negative { value, field: field.to_owned() })
 }
 
-/// Error converting an `i64` to a `u32`.
+/// Error converting an `i64` to a `u32` or `u64`.
 ///
-/// If we expect a numeric value to sanely fit inside a `u32` we use that type in the `model`
-/// module, this requires converting the `i64` returned by the JSONRPC API into a `u32`, if our
-/// expectations are not met this error will be encountered.
+/// The JSONRPC API returns `i64` values. If these values match our expectations, then
+/// we convert them to either `u32` or `u64`, depending on the JSONRPC field. If our
+/// expectations are not met, this error is returned.
 #[derive(Debug)]
 pub enum NumericError {
     /// Expected an unsigned numeric value however the value was negative.