BlockStore: remove getParams() from the hierarchy

Nothing in bitcoinj is using this method and applications should not
be getting their `NetworkParameters` from their storage layer.

core/src/main/java/org/bitcoinj/store/BlockStore.java

@@ -17,7 +17,6 @@
 package org.bitcoinj.store;
 
 import org.bitcoinj.core.BlockChain;
-import org.bitcoinj.core.NetworkParameters;
 import org.bitcoinj.base.Sha256Hash;
 import org.bitcoinj.core.StoredBlock;
 
@@ -60,10 +59,4 @@ public interface BlockStore {
     
     /** Closes the store. */
     void close() throws BlockStoreException;
-
-    /**
-     * Get the {@link NetworkParameters} of this store.
-     * @return The network params.
-     */
-    NetworkParameters getParams();
 }

core/src/main/java/org/bitcoinj/store/MemoryBlockStore.java

@@ -36,16 +36,13 @@ public class MemoryBlockStore implements BlockStore {
         }
     };
     private StoredBlock chainHead;
-    private NetworkParameters params;
 
     public MemoryBlockStore(NetworkParameters params) {
-        // Insert the genesis block.
         try {
             Block genesisHeader = params.getGenesisBlock().cloneAsHeader();
             StoredBlock storedGenesis = new StoredBlock(genesisHeader, genesisHeader.getWork(), 0);
             put(storedGenesis);
             setChainHead(storedGenesis);
-            this.params = params;
         } catch (BlockStoreException | VerificationException e) {
             throw new RuntimeException(e);  // Cannot happen.
         }
@@ -80,9 +77,4 @@ public class MemoryBlockStore implements BlockStore {
     public void close() {
         blockMap = null;
     }
-
-    @Override
-    public NetworkParameters getParams() {
-        return params;
-    }
 }

core/src/main/java/org/bitcoinj/store/MemoryFullPrunedBlockStore.java

@@ -411,11 +411,6 @@ public class MemoryFullPrunedBlockStore implements FullPrunedBlockStore {
         return false;
     }
 
-    @Override
-    public NetworkParameters getParams() {
-        return params;
-    }
-
     @Override
     public Network network() {
         return params.network();

core/src/main/java/org/bitcoinj/store/SPVBlockStore.java

@@ -309,11 +309,6 @@ public class SPVBlockStore implements BlockStore {
         }
     }
 
-    @Override
-    public NetworkParameters getParams() {
-        return params;
-    }
-
     protected static final int RECORD_SIZE = 32 /* hash */ + StoredBlock.COMPACT_SERIALIZED_SIZE;
 
     // File format: