public FormBodyPartBuilder setBody(final ContentBody body) {
        this.body = body;
        return this;
    }
Creates a new builder instance with the specified name, content body, and multipart mode.

@param name the name of the form field
@param body the content body of the part
@param mode the {@link HttpMultipartMode} to use, determining filename encoding behavior;

@return a new {@code FormBodyPartBuilder} instance
@since 5.5
httpclient5/src/main/java/org/apache/hc/client5/http/entity/mime/FormBodyPartBuilder.java