Problem parsing json using GsonConverterFactory Retrofit

Question

I want to convert the following JSON result to Pojos in Retrofit:

{
    "status": "success",
    "body": {
        "token": "Bearer eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJhdWQi",
        "profile": [
            {
                "id": 18,
                "first_name": "",
                "last_name": "",
                "mobile": "0000000",
                "email": null,
                "code_melli": null,
                "image": "http://example.com/image.jpg",
                "address": null,
                "credit": 0,
                "status": "active",
                "gender": "male",
                "role": "customer",
                "created_at": "2020-02-02"
            }
        ]
    }
}

My model classes are as follow:

public class Customer {

    @SerializedName("status")
    private String status;
    @SerializedName("body")
    private Body body;

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public Body getBody() {
        return body;
    }

    public void setBody(Body body) {
        this.body = body;
    }

}

and the Body,

public class Body {

    @SerializedName("token")
    private String token;
    @SerializedName("profile")
    private List<Profile> profile = null;

    public String getToken() {
        return token;
    }

    public void setToken(String token) {
        this.token = token;
    }

    public List<Profile> getProfile() {
        return profile;
    }

    public void setProfile(List<Profile> profile) {
        this.profile = profile;
    }

}

and Profile is,

 public class Profile {



         @SerializedName("id")
            @Nullable
            private Integer id;
            @SerializedName("first_name")
            @Nullable
            private String firstName;
            @SerializedName("last_name")
        @Nullable
        private String lastName;
        @SerializedName("mobile")
        @Nullable
        private String mobile;
        @SerializedName("email")
        @Nullable
        private Object email;
        @SerializedName("code_melli")
        @Nullable
        private Object codeMelli;
        @SerializedName("image")
        @Nullable
        private String image;
        @SerializedName("address")
        @Nullable
        private Object address;
        @SerializedName("credit")
        @Nullable
        private Integer credit;
        @SerializedName("status")
        @Nullable
        private String status;
        @SerializedName("gender")
        @Nullable
        private String gender;
        @SerializedName("role")
        @Nullable
        private String role;
        @SerializedName("created_at")
        @Nullable
        private String createdAt;

        public Integer getId() {
            return id;
        }

        public void setId(Integer id) {
            this.id = id;
        }

        public String getFirstName() {
            return firstName;
        }

        public void setFirstName(String firstName) {
            this.firstName = firstName;
        }

        public String getLastName() {
            return lastName;
        }

        public void setLastName(String lastName) {
            this.lastName = lastName;
        }

        public String getMobile() {
            return mobile;
        }

        public void setMobile(String mobile) {
            this.mobile = mobile;
        }

        public Object getEmail() {
            return email;
        }

        public void setEmail(Object email) {
            this.email = email;
        }

        public Object getCodeMelli() {
            return codeMelli;
        }

        public void setCodeMelli(Object codeMelli) {
            this.codeMelli = codeMelli;
        }

        public String getImage() {
            return image;
        }

        public void setImage(String image) {
            this.image = image;
        }

        public Object getAddress() {
            return address;
        }

        public void setAddress(Object address) {
            this.address = address;
        }

        public Integer getCredit() {
            return credit;
        }

        public void setCredit(Integer credit) {
            this.credit = credit;
        }

        public String getStatus() {
            return status;
        }

        public void setStatus(String status) {
            this.status = status;
        }

        public String getGender() {
            return gender;
        }

        public void setGender(String gender) {
            this.gender = gender;
        }

        public String getRole() {
            return role;
        }

        public void setRole(String role) {
            this.role = role;
        }

        public String getCreatedAt() {
            return createdAt;
        }

        public void setCreatedAt(String createdAt) {
            this.createdAt = createdAt;
        }

But the problem is that in the response I can get the value of status and check it to be equal to success however any method on profile give null pointer exception, the code for accessing profile fields is as follow,

Customer customer = response.body();
 customer.getBody().getProfile().get(0).getFirstName();

Answer 1

I use the following gson for the Retrofit and everythings works

 Gson gson = new GsonBuilder()
                    .serializeNulls()
                    .setLenient()
                    .create();