diff --git a/src/utils/DIDResolver.ts b/src/utils/DIDResolver.ts
index 9d66c50..957ce7d 100644
--- a/src/utils/DIDResolver.ts
+++ b/src/utils/DIDResolver.ts
@@ -13,15 +13,6 @@ import ValueType from "../models/ValueType"
 import * as Web3 from "web3"
 import * as DIDTools from "../utils/DIDTools"
 
-/*
- *
- * Resolve a DID to an URL/DDO or later an internal/extrenal DID
- * :param did: 32 byte value or DID string to resolver, this is part of the ocean DID did:op:<32 byte value>
- * :param max_hop_count: max number of hops allowed to find the destination URL/DDO
- * :return DIDResolved object: URL or DDO of the resolved DID
- * :return null: if the DID cannot be resolved
- *
- */
 export default class DIDResolver {
 
     public didRegistry
@@ -29,6 +20,17 @@ export default class DIDResolver {
         this.didRegistry = didRegistry
     }
 
+    /*
+     *
+     * Resolve a DID to an URL/DDO or later an internal/extrenal DID
+     *
+     * :param did: 32 byte value or DID string to resolver, this is part of the ocean DID did:op:<32 byte value>
+     * :param max_hop_count: max number of hops allowed to find the destination URL/DDO
+     *
+     * :return DIDResolved object: URL or DDO of the resolved DID
+     * :return null: if the DID cannot be resolved
+     *
+     */
     public async resolve(did: string, maxHopCount?: number): Promise<DIDResolved> {
 
         maxHopCount = maxHopCount ? maxHopCount : 0
@@ -72,7 +74,14 @@ export default class DIDResolver {
         return resolved
     }
 
-    public async getDID(didId): Promise<DIDRecord> {
+    /*
+     * Internal method to get the actual DID record
+     *
+     * :param didId: 32 byte id to find
+     *
+     * :return DIDRecord of the found DID, if not then return null
+     */
+    private async getDID(didId): Promise<DIDRecord> {
 
         let record: DIDRecord = null
 
@@ -80,7 +89,7 @@ export default class DIDResolver {
         const filterOwner: string = await this.didRegistry.getOwner(didId)
         assert(blockNumber > 0 )
 
-        // filter on the blockNumber only
+        // filter on the blockNumber, owner and didId
         const filterOptions = {
             fromBlock: blockNumber,
             toBlock: blockNumber,
@@ -91,6 +100,7 @@ export default class DIDResolver {
         }
         const events = await this.didRegistry.getEventData("DIDAttributeRegistered", filterOptions)
         if ( events && events.length > 0 ) {
+            // only get the last event, since this should be the latest
             const event = events[events.length - 1]
             record = {
                 didId: event.returnValues.did,
@@ -99,7 +109,6 @@ export default class DIDResolver {
                 valueType: ValueType[event.returnValues.valueType],
                 key: event.returnValues.key,
                 value: event.returnValues.value,
-
             } as DIDRecord
         }
         return record
diff --git a/src/utils/DIDTools.ts b/src/utils/DIDTools.ts
index d14638a..72e364d 100644
--- a/src/utils/DIDTools.ts
+++ b/src/utils/DIDTools.ts
@@ -13,18 +13,18 @@ const OCEAN_DID_METHOD = "op"
  * This function generates all types of DID's including ocean DID's
  *
  * :param didId: string to of the 'id' part of the DID
- * :param path: option path part of the DID
- * :param fragment: option fragment of the DID
- * :param method: option method of the DID, defaults to 'op'
+ * :param path: optional path part of the DID
+ * :param fragment: optional fragment of the DID
+ * :param method: optional method of the DID, defaults to 'op'
  *
  * :return string generated DID, in the format did:<method>:<didId>[/<path>][#<fragment>]
  */
 export function didGenerate(didId: string, path?: string, fragment?: string, method?: string) {
-    method = method === undefined ? OCEAN_DID_METHOD : method
+    method = method ? method : OCEAN_DID_METHOD
     method = method.toLowerCase().replace(/[^a-z0-9]/g, "")
     didId = didId.replace(/[^a-zA-Z0-9-.]/g, "")
     const did = ["did:", method, ":", didId]
-    if (path) {
+    if ( path ) {
         did.push("/")
         did.push(path)
     }
@@ -47,7 +47,9 @@ interface IDIDParse {
  * The function didParse will parse all types of DID's including Ocean DID
  * If this is a Ocean DID the function will return record with the value
  * `idHex` set to a hex string ( without the leading 0x ).
+ * 
  * :param did: did string to parse
+ * 
  * :return ParseRecord
  *      method - method of DID
  *      id - id of the DID
@@ -58,9 +60,6 @@ interface IDIDParse {
 export function didParse(did: string): IDIDParse {
 
     let result: IDIDParse = null
-    if ( typeof did !== "string" ) {
-        throw TypeError("DID must be a string")
-    }
     const match = did.match(/^did:([a-z0-9]+):([a-zA-Z0-9-.]+)(.*)/)
     if ( match ) {
 
@@ -84,6 +83,7 @@ export function didParse(did: string): IDIDParse {
  * Validate a Ocean DID, return true if valid, else false
  *
  * :param did: string to validate as an Ocean DID
+ * 
  * :return true if the DID is valid
  */
 export function isDIDValid(did: string): boolean {
@@ -96,11 +96,12 @@ export function isDIDValid(did: string): boolean {
  *
  * :param id: can be a hex string with or without the leading '0x'
  * :param method: if empty, default to 'op'
+ * 
  * :return a valid DID
  * :return '0' for a 0 DID
  */
 export function idToDID(id: string, method?: string): string {
-    method = method === undefined ? OCEAN_DID_METHOD : method
+    method = method ? method : OCEAN_DID_METHOD
     method = method.toLowerCase().replace(/[^a-z0-9]/g, "")
 
     // remove any leading 0x
@@ -123,15 +124,23 @@ export function idToDID(id: string, method?: string): string {
  */
 export function didToId(did: string): string {
     const result = didParse(did)
-    if (result && result.idHex ) {
+    if ( result && result.idHex ) {
         return result.idHex
     }
     return null
 }
 
+/*
+ * Convert an Ocean DID string to 32 bytes
+ * 
+ * :param did: string starting with "did:op:"
+ * 
+ * :return 32 byte array of the Id in the DID
+ * :return null if the DID is a invalid Ocean DID
+ */
 export function didToIdBytes(did: string): Uint8Array {
     const result = didParse(did)
-    if (result && result.idHex) {
+    if ( result && result.idHex ) {
         return Web3.utils.hexToBytes("0x" + result.idHex)
     }
     return null