Running this test code multiple times returns different results:

_{package org.bson.codecs.pojo;}

_{import org.bson.codecs.pojo.annotations.BsonProperty;}

_{public class Test {}

    _{public static final String TEST_ID = "testId";
    public static final String BATCH_ID = "batchId";}

    _{@BsonProperty(TEST_ID)
    private String testId;}

    _{@BsonProperty(BATCH_ID)
    private String batchId;}

    _{public Test(String testId, String batchId) {
        this.testId = testId;
        this.batchId = batchId;
    }}

    _{public String getTestId() {
        return testId;
    }}

    _{public void setTestId(String testId) {
        this.testId = testId;
    }}

    _{public boolean isTestId() {
        return !testId.isEmpty();
    }}

    _{public String getBatchId() {
        return batchId;
    }}

    _{public void setBatchId(String batchId) {
        this.batchId = batchId;
    }}

    _{public boolean isBatchId() {
        return !batchId.isEmpty();
    }}

    _{public static void main(String[] args) {
            PropertyModelBuilder<?> property1 = ClassModel.builder(Test.class).getProperty(BATCH_ID);
            PropertyModelBuilder<?> property2 = ClassModel.builder(Test.class).getProperty(TEST_ID);
            System.out.println(((PropertyAccessorImpl) property1.getPropertyAccessor()).getPropertyMetadata().getError());
            System.out.println(((PropertyAccessorImpl) property2.getPropertyAccessor()).getPropertyMetadata().getError());
    }
}}

Results:{{{}
_{Property 'batchId' in Test, has differing data types: TypeData{type=String} and TypeData{type=Boolean}.
null}{}}}

{{_{null
Property 'testId' in Test, has differing data types: TypeData{type=String} and TypeData{type=Boolean}.}}}

{{_{Property 'batchId' in Test, has differing data types: TypeData{type=String} and TypeData{type=Boolean}.
Property 'testId' in Test, has differing data types: TypeData{type=String} and TypeData{type=Boolean}.}}}

{{_null
null}}