title: How to use "assertThat().body("email", is(email)); to validate some response?
body: <p>I'm trying to validate the JSON response of a POST API that I'm developing the Automation Tests. </p>
  
  <pre><code>public void criarConta(String srtAmbiente, String srtAPI, String srtToken, String srtSenha) {
              System.out.println(srtAmbiente+srtAPI);
              DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
              int length = 15;
              String email = generateRandomEmail(length);
              System.out.println(email);
              Map&lt;String, String&gt; emailContent = new HashMap&lt;String,String&gt;();
              emailContent.put("email", email);
              Map&lt;String, Object&gt; postContent = new HashMap&lt;String,Object&gt;();
              postContent.put("customer", emailContent);
              postContent.put("password", srtSenha);
              RestAssured.given().contentType(ContentType.JSON)
              .header("Authorization", "Bearer "+srtToken)
              .with().body(postContent)
              .when().post(srtAmbiente+srtAPI).prettyPeek()
              .then().statusCode(200).contentType(ContentType.JSON)
              .assertThat().body("email", *is*(email));
      }
  </code></pre>
  
  <p>But my code isn't recognize the "IS" on the last line, I tried to change it to "ContainsString", "equalsTo", but it return the same error. I don't know if is dependency or some import. 
  Can you help me? Thanks!</p>