How to use the datax-common.IconButtonStyles.neutralStyle function in datax-common

renderDeleteSinkerButton() {
        // enable only if there is a sinker selected and its not a metric sinker.
        // we do not allow the user to delete our provided metric sinker.
        const sinker = this.getSinker();
        const enableButton = sinker !== undefined && !Helpers.isMetricSinker(sinker) && this.props.deleteOutputSinkButtonEnabled;

        return (
             this.props.onDeleteSinker(this.props.selectedSinkerIndex)}
            >
                <i style="{enableButton">
                Delete
            </i><i style="{enableButton">
        );
    }
</i>

renderBackButton() {
        const buttonTooltip = this.props.flow.isDirty || this.props.isQueryDirty ? 'Discard Changes' : 'Go Back';
        let buttonText = this.props.flow.isDirty || this.props.isQueryDirty ? 'Cancel' : 'Back';
        let buttonIcon = <i style="{IconButtonStyles.neutralStyle}">;

        if (this.state.loading) {
            // render the button as empty during load but keep it existing so that button toolbar is visible
            buttonText = '';
            buttonIcon = null;
        }

        return (
             this.onCancel()}&gt;
                {buttonIcon}
                {buttonText}
            
        );
    }
</i>

renderDeleteBatchButton() {
        const batch = this.getBatch();
        const enableButton = batch !== undefined && this.props.deleteBatchButtonEnabled;

        return (
             this.props.onDeleteBatch(this.props.selectedBatchIndex)}
            >
                <i style="{enableButton">
                Delete
            </i><i style="{enableButton">
        );
    }
</i>

renderDeleteParamButton(index) {
        return (
             this.onDeleteParam(index)}
            >
                <i style="{IconButtonStyles.neutralStyle}">
            </i><i style="{IconButtonStyles.neutralStyle}">
        );
    }
</i>

renderPreviewCodeGenQueryButton() {
        const display = 'Preview';
        return (
            <div style="{toggleStyle}">
                 this.onUpdatePreviewCodeGenQuery()}
                &gt;
                    <i style="{this.props.previewQueryButtonEnabled">
                    {display}
                </i><i style="{this.props.previewQueryButtonEnabled">
            </i></div><i style="{this.props.previewQueryButtonEnabled">
        );
    }
</i>

renderDeleteFunctionButton() {
        const enableButton = this.props.selectedFunctionIndex !== undefined && this.props.deleteFunctionButtonEnabled;

        return (
             this.props.onDeleteFunction(this.props.selectedFunctionIndex)}
            >
                <i style="{enableButton">
                Delete
            </i><i style="{enableButton">
        );
    }
</i>