def get_pitest_maven_skeleton(class_to_mutate, test_to_run, mutator='ALL', threads=4):
    """Returns the string to inject into the pom to run the mutation analysis

    Arguments
    -------------
    - class_to_mutate: the name of the class
    - test_to_run: the name of the test to run against the mutation
    - mutator: the mutator to use
    - threads: the number of tests to use

    """
    string_to_inject = """
    <plugin>
    <groupId>org.pitest</groupId>
    <artifactId>pitest-maven</artifactId>
    <version>1.3.2</version>
    <configuration>
    <failWhenNoMutations>false</failWhenNoMutations>
    <targetClasses>
    <param>
    """+class_to_mutate+"""
    </param>
    </targetClasses>
    <targetTests>
    <param>
    """+test_to_run+"""
    </param>
    </targetTests>
    <mutators>
    <mutator>
    """+mutator+"""
    </mutator>
    </mutators>
    <avoidCallsTo>
    <threads>"""+str(threads)+"""</threads>
    <avoidCallsTo>java.util.logging</avoidCallsTo>
    <avoidCallsTo>org.apache.log4j</avoidCallsTo>
    <avoidCallsTo>org.slf4j</avoidCallsTo>
    <avoidCallsTo>org.apache.commons.logging</avoidCallsTo>
    </avoidCallsTo>
    </configuration>
    </plugin>
    """
    return string_to_inject