[MINOR] javadoc for kzg precompile (#4988)

* javadoc for kzg precompile

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

datatypes/src/main/java/org/hyperledger/besu/datatypes/Address.java

@@ -70,9 +70,9 @@ public class Address extends DelegatingBytes implements org.hyperledger.besu.plu
   public static final Address BLS12_MAP_FP_TO_G1 = Address.precompiled(0x11);
   /** The constant BLS12_MAP_FP2_TO_G2. */
   public static final Address BLS12_MAP_FP2_TO_G2 = Address.precompiled(0x12);
-
+  /** The constant KZG_POINT_EVAL. */
   public static final Address KZG_POINT_EVAL = Address.precompiled(0x14);
-
+  /** The constant ZERO. */
   public static final Address ZERO = Address.fromHexString("0x0");
 
   /**
@@ -137,10 +137,10 @@ public class Address extends DelegatingBytes implements org.hyperledger.besu.plu
   }
 
   /**
-   * Parse an hexadecimal string representing an account address.
+   * Parse a hexadecimal string representing an account address.
    *
-   * @param str An hexadecimal string (with or without the leading '0x') representing a valid
+   * @param str A hexadecimal string (with or without the leading '0x') representing a valid account
-   *     account address.
+   *     address.
    * @return The parsed address: {@code null} if the provided string is {@code null}.
    * @throws IllegalArgumentException if the string is either not hexadecimal, or not the valid
    *     representation of an address.
@@ -152,9 +152,9 @@ public class Address extends DelegatingBytes implements org.hyperledger.besu.plu
   }
 
   /**
-   * Parse an hexadecimal string representing an account address.
+   * Parse a hexadecimal string representing an account address.
    *
-   * @param str An hexadecimal string representing a valid account address (strictly 20 bytes).
+   * @param str A hexadecimal string representing a valid account address (strictly 20 bytes).
    * @return The parsed address.
    * @throws IllegalArgumentException if the provided string is {@code null}.
    * @throws IllegalArgumentException if the string is either not hexadecimal, or not the valid

evm/src/main/java/org/hyperledger/besu/evm/precompile/KZGPointEvalPrecompiledContract.java

@@ -35,12 +35,19 @@ import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
 import org.jetbrains.annotations.NotNull;
 
+/** The KZGPointEval precompile contract. */
 public class KZGPointEvalPrecompiledContract implements PrecompiledContract {
 
+  /** Instantiates a new KZGPointEval precompile contract. */
   public KZGPointEvalPrecompiledContract() {
     this(Optional.empty());
   }
 
+  /**
+   * Instantiates a new KZGPointEval precompile contract.
+   *
+   * @param pathToTrustedSetup the trusted setup path
+   */
   public KZGPointEvalPrecompiledContract(final Optional<Path> pathToTrustedSetup) {
 
     String absolutePathToSetup;
@@ -85,6 +92,7 @@ public class KZGPointEvalPrecompiledContract implements PrecompiledContract {
     }
   }
 
+  /** free up resources. */
   @VisibleForTesting
   public void tearDown() {
     CKZG4844JNI.freeTrustedSetup();

evm/src/main/java/org/hyperledger/besu/evm/precompile/MainnetPrecompiledContracts.java

@@ -135,6 +135,12 @@ public abstract class MainnetPrecompiledContracts {
     registry.put(Address.BLS12_MAP_FP2_TO_G2, new BLS12MapFp2ToG2PrecompiledContract());
   }
 
+  /**
+   * Populate registry for Cancun.
+   *
+   * @param registry the registry
+   * @param gasCalculator the gas calculator
+   */
   public static void populateForCancun(
       final PrecompileContractRegistry registry, final GasCalculator gasCalculator) {
     populateForIstanbul(registry, gasCalculator);