chain-ethereum: trash dead code in capabilities.rs (#4423)

Author: neysofu

chain/ethereum/src/capabilities.rs

@@ -1,9 +1,6 @@
-use anyhow::Error;
 use graph::impl_slog_value;
 use std::cmp::Ordering;
-use std::collections::BTreeSet;
 use std::fmt;
-use std::str::FromStr;
 
 use crate::DataSource;
 
@@ -17,7 +14,7 @@ pub struct NodeCapabilities {
 /// other. No [`Ord`] (i.e. total order) implementation is applicable.
 impl PartialOrd for NodeCapabilities {
     fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-        product_order([
+        product_order(&[
             self.archive.cmp(&other.archive),
             self.traces.cmp(&other.traces),
         ])
@@ -26,7 +23,7 @@ impl PartialOrd for NodeCapabilities {
 
 /// Defines a [product order](https://en.wikipedia.org/wiki/Product_order) over
 /// an array of [`Ordering`].
-fn product_order<const N: usize>(cmps: [Ordering; N]) -> Option<Ordering> {
+fn product_order(cmps: &[Ordering]) -> Option<Ordering> {
     if cmps.iter().all(|c| c.is_eq()) {
         Some(Ordering::Equal)
     } else if cmps.iter().all(|c| c.is_le()) {
@@ -38,18 +35,6 @@ fn product_order<const N: usize>(cmps: [Ordering; N]) -> Option<Ordering> {
     }
 }
 
-impl FromStr for NodeCapabilities {
-    type Err = Error;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let capabilities: BTreeSet<&str> = s.split(',').collect();
-        Ok(NodeCapabilities {
-            archive: capabilities.contains("archive"),
-            traces: capabilities.contains("traces"),
-        })
-    }
-}
-
 impl fmt::Display for NodeCapabilities {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         let NodeCapabilities { archive, traces } = self;