code: public final void setEntry(String alias, Entry entry,
                          ProtectionParameter protParam)
                  throws KeyStoreException {
          if (alias == null || entry == null) {
              throw new NullPointerException("invalid null input");
          }
          if (!initialized) {
              throw new KeyStoreException("Uninitialized keystore");
          }
          keyStoreSpi.engineSetEntry(alias, entry, protParam);
      }
docs: Saves a keystore <code>Entry</code> under the specified alias.
  The protection parameter is used to protect the
  <code>Entry</code>.
  
  <p> If an entry already exists for the specified alias,
  it is overridden.
  
  @param alias save the keystore <code>Entry</code> under this alias
  @param entry the <code>Entry</code> to save
  @param protParam the <code>ProtectionParameter</code>
  used to protect the <code>Entry</code>,
  which may be <code>null</code>
  
  @exception NullPointerException if
  <code>alias</code> or <code>entry</code>
  is <code>null</code>
  @exception KeyStoreException if the keystore has not been initialized
  (loaded), or if this operation fails for some other reason
  
  @see #getEntry(String, KeyStore.ProtectionParameter)
  
  @since 1.5