solution: better order of availability status

src/main/kotlin/io/emeraldpay/dshackle/upstream/UpstreamAvailability.kt

@@ -2,10 +2,25 @@ package io.emeraldpay.dshackle.upstream
 
 enum class UpstreamAvailability(val grpcId: Int) {
 
+    /**
+     * Active fully synchronized node
+     */
     OK(1),
-    IMMATURE(2),
+    /**
-    SYNCING(3),
+     * Good node, but is still synchronizing a latest block
-    LAGGING(4),
+     */
+    LAGGING(2),
+    /**
+     * May be good, but node doesn't have enough peers to be sure it's on corrected chain
+     */
+    IMMATURE(3),
+    /**
+     * Node is doing it's initial synchronization, is behind by at least several blocks
+     */
+    SYNCING(4),
+    /**
+     * Unavailable node
+     */
     UNAVAILABLE(5);
 
     companion object {

src/test/groovy/io/emeraldpay/dshackle/upstream/UpstreamAvailabilitySpec.groovy

@@ -6,10 +6,10 @@ class UpstreamAvailabilitySpec extends Specification {
 
     def "Defined order"() {
         expect:
-        UpstreamAvailability.OK.compareTo(UpstreamAvailability.IMMATURE) < 0
+        UpstreamAvailability.OK.compareTo(UpstreamAvailability.LAGGING) < 0
+        UpstreamAvailability.LAGGING.compareTo(UpstreamAvailability.IMMATURE) < 0
         UpstreamAvailability.IMMATURE.compareTo(UpstreamAvailability.SYNCING) < 0
-        UpstreamAvailability.SYNCING.compareTo(UpstreamAvailability.LAGGING) < 0
+        UpstreamAvailability.SYNCING.compareTo(UpstreamAvailability.UNAVAILABLE) < 0
-        UpstreamAvailability.LAGGING.compareTo(UpstreamAvailability.UNAVAILABLE) < 0
 
         UpstreamAvailability.OK.compareTo(UpstreamAvailability.UNAVAILABLE) < 0
         UpstreamAvailability.UNAVAILABLE.compareTo(UpstreamAvailability.OK) > 0